diff options
| author | John Ericson <John.Ericson@Obsidian.Systems> | 2023-01-06 10:35:20 -0500 |
|---|---|---|
| committer | John Ericson <John.Ericson@Obsidian.Systems> | 2023-01-06 10:35:20 -0500 |
| commit | e9fc1e4fdb0ab5adb6b163c3db361b86a4f5c69b (patch) | |
| tree | 25522f96d7aa54f7c93ba3c5e187374d3a50dfe6 /doc/manual | |
| parent | 55caef36ed1cee2e924c82cf49b3ceb17bdde910 (diff) | |
| parent | 3172c51baff5c81362fcdafa2e28773c2949c660 (diff) | |
Merge remote-tracking branch 'upstream/master' into path-info
Diffstat (limited to 'doc/manual')
52 files changed, 2490 insertions, 1078 deletions
diff --git a/doc/manual/anchors.jq b/doc/manual/anchors.jq new file mode 100755 index 000000000..72309779c --- /dev/null +++ b/doc/manual/anchors.jq @@ -0,0 +1,31 @@ +"\\[\\]\\{#(?<anchor>[^\\}]+?)\\}" as $empty_anchor_regex | +"\\[(?<text>[^\\]]+?)\\]\\{#(?<anchor>[^\\}]+?)\\}" as $anchor_regex | + + +def transform_anchors_html: + . | gsub($empty_anchor_regex; "<a name=\"" + .anchor + "\"></a>") + | gsub($anchor_regex; "<a href=\"#" + .anchor + "\" id=\"" + .anchor + "\">" + .text + "</a>"); + + +def transform_anchors_strip: + . | gsub($empty_anchor_regex; "") + | gsub($anchor_regex; .text); + + +def map_contents_recursively(transformer): + . + { + Chapter: (.Chapter + { + content: .Chapter.content | transformer, + sub_items: .Chapter.sub_items | map(map_contents_recursively(transformer)), + }), + }; + + +def process_command: + .[0] as $context | + .[1] as $body | + $body + { + sections: $body.sections | map(map_contents_recursively(if $context.renderer == "html" then transform_anchors_html else transform_anchors_strip end)), + }; + +process_command diff --git a/doc/manual/book.toml b/doc/manual/book.toml index fee41dfb3..46ced7ff7 100644 --- a/doc/manual/book.toml +++ b/doc/manual/book.toml @@ -1,2 +1,12 @@ +[book] +title = "Nix Reference Manual" + [output.html] additional-css = ["custom.css"] +additional-js = ["redirects.js"] +edit-url-template = "https://github.com/NixOS/nix/tree/master/doc/manual/{path}" +git-repository-url = "https://github.com/NixOS/nix" + +[preprocessor.anchors] +renderers = ["html"] +command = "jq --from-file doc/manual/anchors.jq" diff --git a/doc/manual/generate-builtins.nix b/doc/manual/generate-builtins.nix index 6c8b88da2..115bb3f94 100644 --- a/doc/manual/generate-builtins.nix +++ b/doc/manual/generate-builtins.nix @@ -1,16 +1,20 @@ -with builtins; -with import ./utils.nix; +builtinsDump: +let + showBuiltin = name: + let + inherit (builtinsDump.${name}) doc args; + in + '' + <dt id="builtins-${name}"> + <a href="#builtins-${name}"><code>${name} ${listArgs args}</code></a> + </dt> + <dd> -builtins: + ${doc} + + </dd> + ''; + listArgs = args: builtins.concatStringsSep " " (map (s: "<var>${s}</var>") args); +in +with builtins; concatStringsSep "\n" (map showBuiltin (attrNames builtinsDump)) -concatStrings (map - (name: - let builtin = builtins.${name}; in - "<dt id=\"builtins-${name}\"><a href=\"#builtins-${name}\"><code>${name} " - + concatStringsSep " " (map (s: "<var>${s}</var>") builtin.args) - + "</code></a></dt>" - + "<dd>\n\n" - + builtin.doc - + "\n\n</dd>" - ) - (attrNames builtins)) diff --git a/doc/manual/generate-manpage.nix b/doc/manual/generate-manpage.nix index 244cfa0c2..8c7c4d358 100644 --- a/doc/manual/generate-manpage.nix +++ b/doc/manual/generate-manpage.nix @@ -1,99 +1,115 @@ -{ command, renderLinks ? false }: +{ toplevel }: with builtins; with import ./utils.nix; let - showCommand = - { command, def, filename }: - '' - **Warning**: This program is **experimental** and its interface is subject to change. - '' - + "# Name\n\n" - + "`${command}` - ${def.description}\n\n" - + "# Synopsis\n\n" - + showSynopsis { inherit command; args = def.args; } - + (if def.commands or {} != {} - then - let - categories = sort (x: y: x.id < y.id) (unique (map (cmd: cmd.category) (attrValues def.commands))); - listCommands = cmds: - concatStrings (map (name: - "* " - + (if renderLinks - then "[`${command} ${name}`](./${appendName filename name}.md)" - else "`${command} ${name}`") - + " - ${cmds.${name}.description}\n") - (attrNames cmds)); - in - "where *subcommand* is one of the following:\n\n" - # FIXME: group by category - + (if length categories > 1 - then - concatStrings (map - (cat: - "**${toString cat.description}:**\n\n" - + listCommands (filterAttrs (n: v: v.category == cat) def.commands) - + "\n" - ) categories) - + "\n" - else - listCommands def.commands - + "\n") - else "") - + (if def ? doc - then def.doc + "\n\n" - else "") - + (let s = showOptions def.flags; in - if s != "" - then "# Options\n\n${s}" - else "") - ; + showCommand = { command, details, filename, toplevel }: + let + result = '' + > **Warning** \ + > This program is **experimental** and its interface is subject to change. + + # Name + + `${command}` - ${details.description} + + # Synopsis + + ${showSynopsis command details.args} + + ${maybeSubcommands} + + ${maybeDocumentation} + + ${maybeOptions} + ''; + showSynopsis = command: args: + let + showArgument = arg: "*${arg.label}*" + (if arg ? arity then "" else "..."); + arguments = concatStringsSep " " (map showArgument args); + in '' + `${command}` [*option*...] ${arguments} + ''; + maybeSubcommands = if details ? commands && details.commands != {} + then '' + where *subcommand* is one of the following: + + ${subcommands} + '' + else ""; + subcommands = if length categories > 1 + then listCategories + else listSubcommands details.commands; + categories = sort (x: y: x.id < y.id) (unique (map (cmd: cmd.category) (attrValues details.commands))); + listCategories = concatStrings (map showCategory categories); + showCategory = cat: '' + **${toString cat.description}:** + + ${listSubcommands (filterAttrs (n: v: v.category == cat) details.commands)} + ''; + listSubcommands = cmds: concatStrings (attrValues (mapAttrs showSubcommand cmds)); + showSubcommand = name: subcmd: '' + * [`${command} ${name}`](./${appendName filename name}.md) - ${subcmd.description} + ''; + maybeDocumentation = if details ? doc then details.doc else ""; + maybeOptions = if details.flags == {} then "" else '' + # Options + + ${showOptions details.flags toplevel.flags} + ''; + showOptions = options: commonOptions: + let + allOptions = options // commonOptions; + showCategory = cat: '' + ${if cat != "" then "**${cat}:**" else ""} + + ${listOptions (filterAttrs (n: v: v.category == cat) allOptions)} + ''; + listOptions = opts: concatStringsSep "\n" (attrValues (mapAttrs showOption opts)); + showOption = name: option: + let + shortName = if option ? shortName then "/ `-${option.shortName}`" else ""; + labels = if option ? labels then (concatStringsSep " " (map (s: "*${s}*") option.labels)) else ""; + in trim '' + - `--${name}` ${shortName} ${labels} + + ${option.description} + ''; + categories = sort builtins.lessThan (unique (map (cmd: cmd.category) (attrValues allOptions))); + in concatStrings (map showCategory categories); + in squash result; appendName = filename: name: (if filename == "nix" then "nix3" else filename) + "-" + name; - showOptions = flags: + processCommand = { command, details, filename, toplevel }: let - categories = sort builtins.lessThan (unique (map (cmd: cmd.category) (attrValues flags))); - in - concatStrings (map - (cat: - (if cat != "" - then "**${cat}:**\n\n" - else "") - + concatStrings - (map (longName: - let - flag = flags.${longName}; - in - " - `--${longName}`" - + (if flag ? shortName then " / `-${flag.shortName}`" else "") - + (if flag ? labels then " " + (concatStringsSep " " (map (s: "*${s}*") flag.labels)) else "") - + " \n" - + " " + flag.description + "\n\n" - ) (attrNames (filterAttrs (n: v: v.category == cat) flags)))) - categories); - - showSynopsis = - { command, args }: - "`${command}` [*option*...] ${concatStringsSep " " - (map (arg: "*${arg.label}*" + (if arg ? arity then "" else "...")) args)}\n\n"; - - processCommand = { command, def, filename }: - [ { name = filename + ".md"; value = showCommand { inherit command def filename; }; inherit command; } ] - ++ concatMap - (name: processCommand { - filename = appendName filename name; - command = command + " " + name; - def = def.commands.${name}; - }) - (attrNames def.commands or {}); - -in + cmd = { + inherit command; + name = filename + ".md"; + value = showCommand { inherit command details filename toplevel; }; + }; + subcommand = subCmd: processCommand { + command = command + " " + subCmd; + details = details.commands.${subCmd}; + filename = appendName filename subCmd; + inherit toplevel; + }; + in [ cmd ] ++ concatMap subcommand (attrNames details.commands or {}); -let - manpages = processCommand { filename = "nix"; command = "nix"; def = builtins.fromJSON command; }; - summary = concatStrings (map (manpage: " - [${manpage.command}](command-ref/new-cli/${manpage.name})\n") manpages); -in -(listToAttrs manpages) // { "SUMMARY.md" = summary; } + parsedToplevel = builtins.fromJSON toplevel; + + manpages = processCommand { + command = "nix"; + details = parsedToplevel; + filename = "nix"; + toplevel = parsedToplevel; + }; + + tableOfContents = let + showEntry = page: + " - [${page.command}](command-ref/new-cli/${page.name})"; + in concatStringsSep "\n" (map showEntry manpages) + "\n"; + +in (listToAttrs manpages) // { "SUMMARY.md" = tableOfContents; } diff --git a/doc/manual/generate-options.nix b/doc/manual/generate-options.nix index 2d586fa1b..a4ec36477 100644 --- a/doc/manual/generate-options.nix +++ b/doc/manual/generate-options.nix @@ -1,29 +1,41 @@ -with builtins; -with import ./utils.nix; +let + inherit (builtins) attrNames concatStringsSep isAttrs isBool; + inherit (import ./utils.nix) concatStrings squash splitLines; +in -options: +optionsInfo: +let + showOption = name: + let + inherit (optionsInfo.${name}) description documentDefault defaultValue aliases; + result = squash '' + - <span id="conf-${name}">[`${name}`](#conf-${name})</span> -concatStrings (map - (name: - let option = options.${name}; in - " - [`${name}`](#conf-${name})" - + "<p id=\"conf-${name}\"></p>\n\n" - + concatStrings (map (s: " ${s}\n") (splitLines option.description)) + "\n\n" - + (if option.documentDefault - then " **Default:** " + ( - if option.value == "" || option.value == [] - then "*empty*" - else if isBool option.value - then (if option.value then "`true`" else "`false`") - else - # n.b. a StringMap value type is specified as a string, but - # this shows the value type. The empty stringmap is "null" in - # JSON, but that converts to "{ }" here. - (if isAttrs option.value then "`\"\"`" - else "`" + toString option.value + "`")) + "\n\n" - else " **Default:** *machine-specific*\n") - + (if option.aliases != [] - then " **Deprecated alias:** " + (concatStringsSep ", " (map (s: "`${s}`") option.aliases)) + "\n\n" - else "") - ) - (attrNames options)) + ${indent " " body} + ''; + # separate body to cleanly handle indentation + body = '' + ${description} + + **Default:** ${showDefault documentDefault defaultValue} + + ${showAliases aliases} + ''; + showDefault = documentDefault: defaultValue: + if documentDefault then + # a StringMap value type is specified as a string, but + # this shows the value type. The empty stringmap is `null` in + # JSON, but that converts to `{ }` here. + if defaultValue == "" || defaultValue == [] || isAttrs defaultValue + then "*empty*" + else if isBool defaultValue then + if defaultValue then "`true`" else "`false`" + else "`${toString defaultValue}`" + else "*machine-specific*"; + showAliases = aliases: + if aliases == [] then "" else + "**Deprecated alias:** ${(concatStringsSep ", " (map (s: "`${s}`") aliases))}"; + indent = prefix: s: + concatStringsSep "\n" (map (x: if x == "" then x else "${prefix}${x}") (splitLines s)); + in result; +in concatStrings (map showOption (attrNames optionsInfo)) diff --git a/doc/manual/local.mk b/doc/manual/local.mk index c1ce8aaeb..c0f69e00f 100644 --- a/doc/manual/local.mk +++ b/doc/manual/local.mk @@ -1,5 +1,9 @@ ifeq ($(doc_generate),yes) +MANUAL_SRCS := \ + $(call rwildcard, $(d)/src, *.md) \ + $(call rwildcard, $(d)/src, */*.md) + # Generate man pages. man-pages := $(foreach n, \ nix-env.1 nix-build.1 nix-shell.1 nix-store.1 nix-instantiate.1 \ @@ -25,19 +29,19 @@ nix-eval = $(dummy-env) $(bindir)/nix eval --experimental-features nix-command - $(d)/%.1: $(d)/src/command-ref/%.md @printf "Title: %s\n\n" "$$(basename $@ .1)" > $^.tmp @cat $^ >> $^.tmp - $(trace-gen) lowdown -sT man -M section=1 $^.tmp -o $@ + $(trace-gen) lowdown -sT man --nroff-nolinks -M section=1 $^.tmp -o $@ @rm $^.tmp $(d)/%.8: $(d)/src/command-ref/%.md @printf "Title: %s\n\n" "$$(basename $@ .8)" > $^.tmp @cat $^ >> $^.tmp - $(trace-gen) lowdown -sT man -M section=8 $^.tmp -o $@ + $(trace-gen) lowdown -sT man --nroff-nolinks -M section=8 $^.tmp -o $@ @rm $^.tmp $(d)/nix.conf.5: $(d)/src/command-ref/conf-file.md @printf "Title: %s\n\n" "$$(basename $@ .5)" > $^.tmp @cat $^ >> $^.tmp - $(trace-gen) lowdown -sT man -M section=5 $^.tmp -o $@ + $(trace-gen) lowdown -sT man --nroff-nolinks -M section=5 $^.tmp -o $@ @rm $^.tmp $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli @@ -46,7 +50,7 @@ $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli $(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/generate-manpage.nix $(bindir)/nix @rm -rf $@ - $(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix { command = builtins.readFile $<; renderLinks = true; }' + $(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix { toplevel = builtins.readFile $<; }' $(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/generate-options.nix $(d)/src/command-ref/conf-file-prefix.md $(bindir)/nix @cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp @@ -61,10 +65,10 @@ $(d)/conf-file.json: $(bindir)/nix $(trace-gen) $(dummy-env) $(bindir)/nix show-config --json --experimental-features nix-command > $@.tmp @mv $@.tmp $@ -$(d)/src/expressions/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/expressions/builtins-prefix.md $(bindir)/nix - @cat doc/manual/src/expressions/builtins-prefix.md > $@.tmp +$(d)/src/language/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(bindir)/nix + @cat doc/manual/src/language/builtins-prefix.md > $@.tmp $(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp - @cat doc/manual/src/expressions/builtins-suffix.md >> $@.tmp + @cat doc/manual/src/language/builtins-suffix.md >> $@.tmp @mv $@.tmp $@ $(d)/builtins.json: $(bindir)/nix @@ -92,12 +96,12 @@ doc/manual/generated/man1/nix3-manpages: $(d)/src/command-ref/new-cli if [[ $$name = SUMMARY ]]; then continue; fi; \ printf "Title: %s\n\n" "$$name" > $$tmpFile; \ cat $$i >> $$tmpFile; \ - lowdown -sT man -M section=1 $$tmpFile -o $(DESTDIR)$$(dirname $@)/$$name.1; \ + lowdown -sT man --nroff-nolinks -M section=1 $$tmpFile -o $(DESTDIR)$$(dirname $@)/$$name.1; \ rm $$tmpFile; \ done @touch $@ -$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/command-ref/conf-file.md $(d)/src/expressions/builtins.md $(call rwildcard, $(d)/src, *.md) +$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/anchors.jq $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/command-ref/conf-file.md $(d)/src/language/builtins.md $(trace-gen) RUST_LOG=warn mdbook build doc/manual -d $(DESTDIR)$(docdir)/manual endif diff --git a/doc/manual/redirects.js b/doc/manual/redirects.js new file mode 100644 index 000000000..69f75d3a0 --- /dev/null +++ b/doc/manual/redirects.js @@ -0,0 +1,421 @@ +// redirect rules for anchors ensure backwards compatibility of URLs. +// this must be done on the client side, as web servers do not see the anchor part of the URL. + +// redirections are declared as follows: +// each entry has as its key a path matching the requested URL path, relative to the mdBook document root. +// +// IMPORTANT: it must specify the full path with file name and suffix +// +// each entry is itself a set of key-value pairs, where +// - keys are anchors on the matched path. +// - values are redirection targets relative to the current path. + +const redirects = { + "index.html": { + "part-advanced-topics": "advanced-topics/advanced-topics.html", + "chap-tuning-cores-and-jobs": "advanced-topics/cores-vs-jobs.html", + "chap-diff-hook": "advanced-topics/diff-hook.html", + "check-dirs-are-unregistered": "advanced-topics/diff-hook.html#check-dirs-are-unregistered", + "chap-distributed-builds": "advanced-topics/distributed-builds.html", + "chap-post-build-hook": "advanced-topics/post-build-hook.html", + "chap-post-build-hook-caveats": "advanced-topics/post-build-hook.html#implementation-caveats", + "part-command-ref": "command-ref/command-ref.html", + "conf-allow-import-from-derivation": "command-ref/conf-file.html#conf-allow-import-from-derivation", + "conf-allow-new-privileges": "command-ref/conf-file.html#conf-allow-new-privileges", + "conf-allowed-uris": "command-ref/conf-file.html#conf-allowed-uris", + "conf-allowed-users": "command-ref/conf-file.html#conf-allowed-users", + "conf-auto-optimise-store": "command-ref/conf-file.html#conf-auto-optimise-store", + "conf-binary-cache-public-keys": "command-ref/conf-file.html#conf-binary-cache-public-keys", + "conf-binary-caches": "command-ref/conf-file.html#conf-binary-caches", + "conf-build-compress-log": "command-ref/conf-file.html#conf-build-compress-log", + "conf-build-cores": "command-ref/conf-file.html#conf-build-cores", + "conf-build-extra-chroot-dirs": "command-ref/conf-file.html#conf-build-extra-chroot-dirs", + "conf-build-extra-sandbox-paths": "command-ref/conf-file.html#conf-build-extra-sandbox-paths", + "conf-build-fallback": "command-ref/conf-file.html#conf-build-fallback", + "conf-build-max-jobs": "command-ref/conf-file.html#conf-build-max-jobs", + "conf-build-max-log-size": "command-ref/conf-file.html#conf-build-max-log-size", + "conf-build-max-silent-time": "command-ref/conf-file.html#conf-build-max-silent-time", + "conf-build-timeout": "command-ref/conf-file.html#conf-build-timeout", + "conf-build-use-chroot": "command-ref/conf-file.html#conf-build-use-chroot", + "conf-build-use-sandbox": "command-ref/conf-file.html#conf-build-use-sandbox", + "conf-build-use-substitutes": "command-ref/conf-file.html#conf-build-use-substitutes", + "conf-build-users-group": "command-ref/conf-file.html#conf-build-users-group", + "conf-builders": "command-ref/conf-file.html#conf-builders", + "conf-builders-use-substitutes": "command-ref/conf-file.html#conf-builders-use-substitutes", + "conf-compress-build-log": "command-ref/conf-file.html#conf-compress-build-log", + "conf-connect-timeout": "command-ref/conf-file.html#conf-connect-timeout", + "conf-cores": "command-ref/conf-file.html#conf-cores", + "conf-diff-hook": "command-ref/conf-file.html#conf-diff-hook", + "conf-env-keep-derivations": "command-ref/conf-file.html#conf-env-keep-derivations", + "conf-extra-binary-caches": "command-ref/conf-file.html#conf-extra-binary-caches", + "conf-extra-platforms": "command-ref/conf-file.html#conf-extra-platforms", + "conf-extra-sandbox-paths": "command-ref/conf-file.html#conf-extra-sandbox-paths", + "conf-extra-substituters": "command-ref/conf-file.html#conf-extra-substituters", + "conf-fallback": "command-ref/conf-file.html#conf-fallback", + "conf-fsync-metadata": "command-ref/conf-file.html#conf-fsync-metadata", + "conf-gc-keep-derivations": "command-ref/conf-file.html#conf-gc-keep-derivations", + "conf-gc-keep-outputs": "command-ref/conf-file.html#conf-gc-keep-outputs", + "conf-hashed-mirrors": "command-ref/conf-file.html#conf-hashed-mirrors", + "conf-http-connections": "command-ref/conf-file.html#conf-http-connections", + "conf-keep-build-log": "command-ref/conf-file.html#conf-keep-build-log", + "conf-keep-derivations": "command-ref/conf-file.html#conf-keep-derivations", + "conf-keep-env-derivations": "command-ref/conf-file.html#conf-keep-env-derivations", + "conf-keep-outputs": "command-ref/conf-file.html#conf-keep-outputs", + "conf-max-build-log-size": "command-ref/conf-file.html#conf-max-build-log-size", + "conf-max-free": "command-ref/conf-file.html#conf-max-free", + "conf-max-jobs": "command-ref/conf-file.html#conf-max-jobs", + "conf-max-silent-time": "command-ref/conf-file.html#conf-max-silent-time", + "conf-min-free": "command-ref/conf-file.html#conf-min-free", + "conf-narinfo-cache-negative-ttl": "command-ref/conf-file.html#conf-narinfo-cache-negative-ttl", + "conf-narinfo-cache-positive-ttl": "command-ref/conf-file.html#conf-narinfo-cache-positive-ttl", + "conf-netrc-file": "command-ref/conf-file.html#conf-netrc-file", + "conf-plugin-files": "command-ref/conf-file.html#conf-plugin-files", + "conf-post-build-hook": "command-ref/conf-file.html#conf-post-build-hook", + "conf-pre-build-hook": "command-ref/conf-file.html#conf-pre-build-hook", + "conf-require-sigs": "command-ref/conf-file.html#conf-require-sigs", + "conf-restrict-eval": "command-ref/conf-file.html#conf-restrict-eval", + "conf-run-diff-hook": "command-ref/conf-file.html#conf-run-diff-hook", + "conf-sandbox": "command-ref/conf-file.html#conf-sandbox", + "conf-sandbox-dev-shm-size": "command-ref/conf-file.html#conf-sandbox-dev-shm-size", + "conf-sandbox-paths": "command-ref/conf-file.html#conf-sandbox-paths", + "conf-secret-key-files": "command-ref/conf-file.html#conf-secret-key-files", + "conf-show-trace": "command-ref/conf-file.html#conf-show-trace", + "conf-stalled-download-timeout": "command-ref/conf-file.html#conf-stalled-download-timeout", + "conf-substitute": "command-ref/conf-file.html#conf-substitute", + "conf-substituters": "command-ref/conf-file.html#conf-substituters", + "conf-system": "command-ref/conf-file.html#conf-system", + "conf-system-features": "command-ref/conf-file.html#conf-system-features", + "conf-tarball-ttl": "command-ref/conf-file.html#conf-tarball-ttl", + "conf-timeout": "command-ref/conf-file.html#conf-timeout", + "conf-trace-function-calls": "command-ref/conf-file.html#conf-trace-function-calls", + "conf-trusted-binary-caches": "command-ref/conf-file.html#conf-trusted-binary-caches", + "conf-trusted-public-keys": "command-ref/conf-file.html#conf-trusted-public-keys", + "conf-trusted-substituters": "command-ref/conf-file.html#conf-trusted-substituters", + "conf-trusted-users": "command-ref/conf-file.html#conf-trusted-users", + "extra-sandbox-paths": "command-ref/conf-file.html#extra-sandbox-paths", + "sec-conf-file": "command-ref/conf-file.html", + "env-NIX_PATH": "command-ref/env-common.html#env-NIX_PATH", + "env-common": "command-ref/env-common.html", + "envar-remote": "command-ref/env-common.html#env-NIX_REMOTE", + "sec-common-env": "command-ref/env-common.html", + "ch-files": "command-ref/files.html", + "ch-main-commands": "command-ref/main-commands.html", + "opt-out-link": "command-ref/nix-build.html#opt-out-link", + "sec-nix-build": "command-ref/nix-build.html", + "sec-nix-channel": "command-ref/nix-channel.html", + "sec-nix-collect-garbage": "command-ref/nix-collect-garbage.html", + "sec-nix-copy-closure": "command-ref/nix-copy-closure.html", + "sec-nix-daemon": "command-ref/nix-daemon.html", + "refsec-nix-env-install-examples": "command-ref/nix-env.html#examples", + "rsec-nix-env-install": "command-ref/nix-env.html#operation---install", + "rsec-nix-env-set": "command-ref/nix-env.html#operation---set", + "rsec-nix-env-set-flag": "command-ref/nix-env.html#operation---set-flag", + "rsec-nix-env-upgrade": "command-ref/nix-env.html#operation---upgrade", + "sec-nix-env": "command-ref/nix-env.html", + "ssec-version-comparisons": "command-ref/nix-env.html#versions", + "sec-nix-hash": "command-ref/nix-hash.html", + "sec-nix-instantiate": "command-ref/nix-instantiate.html", + "sec-nix-prefetch-url": "command-ref/nix-prefetch-url.html", + "sec-nix-shell": "command-ref/nix-shell.html", + "ssec-nix-shell-shebang": "command-ref/nix-shell.html#use-as-a--interpreter", + "nixref-queries": "command-ref/nix-store.html#queries", + "opt-add-root": "command-ref/nix-store.html#opt-add-root", + "refsec-nix-store-dump": "command-ref/nix-store.html#operation---dump", + "refsec-nix-store-export": "command-ref/nix-store.html#operation---export", + "refsec-nix-store-import": "command-ref/nix-store.html#operation---import", + "refsec-nix-store-query": "command-ref/nix-store.html#operation---query", + "refsec-nix-store-verify": "command-ref/nix-store.html#operation---verify", + "rsec-nix-store-gc": "command-ref/nix-store.html#operation---gc", + "rsec-nix-store-generate-binary-cache-key": "command-ref/nix-store.html#operation---generate-binary-cache-key", + "rsec-nix-store-realise": "command-ref/nix-store.html#operation---realise", + "rsec-nix-store-serve": "command-ref/nix-store.html#operation---serve", + "sec-nix-store": "command-ref/nix-store.html", + "opt-I": "command-ref/opt-common.html#opt-I", + "opt-attr": "command-ref/opt-common.html#opt-attr", + "opt-common": "command-ref/opt-common.html", + "opt-cores": "command-ref/opt-common.html#opt-cores", + "opt-log-format": "command-ref/opt-common.html#opt-log-format", + "opt-max-jobs": "command-ref/opt-common.html#opt-max-jobs", + "opt-max-silent-time": "command-ref/opt-common.html#opt-max-silent-time", + "opt-timeout": "command-ref/opt-common.html#opt-timeout", + "sec-common-options": "command-ref/opt-common.html", + "ch-utilities": "command-ref/utilities.html", + "chap-hacking": "contributing/hacking.html", + "adv-attr-allowSubstitutes": "language/advanced-attributes.html#adv-attr-allowSubstitutes", + "adv-attr-allowedReferences": "language/advanced-attributes.html#adv-attr-allowedReferences", + "adv-attr-allowedRequisites": "language/advanced-attributes.html#adv-attr-allowedRequisites", + "adv-attr-disallowedReferences": "language/advanced-attributes.html#adv-attr-disallowedReferences", + "adv-attr-disallowedRequisites": "language/advanced-attributes.html#adv-attr-disallowedRequisites", + "adv-attr-exportReferencesGraph": "language/advanced-attributes.html#adv-attr-exportReferencesGraph", + "adv-attr-impureEnvVars": "language/advanced-attributes.html#adv-attr-impureEnvVars", + "adv-attr-outputHash": "language/advanced-attributes.html#adv-attr-outputHash", + "adv-attr-outputHashAlgo": "language/advanced-attributes.html#adv-attr-outputHashAlgo", + "adv-attr-outputHashMode": "language/advanced-attributes.html#adv-attr-outputHashMode", + "adv-attr-passAsFile": "language/advanced-attributes.html#adv-attr-passAsFile", + "adv-attr-preferLocalBuild": "language/advanced-attributes.html#adv-attr-preferLocalBuild", + "fixed-output-drvs": "language/advanced-attributes.html#adv-attr-outputHash", + "sec-advanced-attributes": "language/advanced-attributes.html", + "builtin-abort": "language/builtins.html#builtins-abort", + "builtin-add": "language/builtins.html#builtins-add", + "builtin-all": "language/builtins.html#builtins-all", + "builtin-any": "language/builtins.html#builtins-any", + "builtin-attrNames": "language/builtins.html#builtins-attrNames", + "builtin-attrValues": "language/builtins.html#builtins-attrValues", + "builtin-baseNameOf": "language/builtins.html#builtins-baseNameOf", + "builtin-bitAnd": "language/builtins.html#builtins-bitAnd", + "builtin-bitOr": "language/builtins.html#builtins-bitOr", + "builtin-bitXor": "language/builtins.html#builtins-bitXor", + "builtin-builtins": "language/builtins.html#builtins-builtins", + "builtin-compareVersions": "language/builtins.html#builtins-compareVersions", + "builtin-concatLists": "language/builtins.html#builtins-concatLists", + "builtin-concatStringsSep": "language/builtins.html#builtins-concatStringsSep", + "builtin-currentSystem": "language/builtins.html#builtins-currentSystem", + "builtin-deepSeq": "language/builtins.html#builtins-deepSeq", + "builtin-derivation": "language/builtins.html#builtins-derivation", + "builtin-dirOf": "language/builtins.html#builtins-dirOf", + "builtin-div": "language/builtins.html#builtins-div", + "builtin-elem": "language/builtins.html#builtins-elem", + "builtin-elemAt": "language/builtins.html#builtins-elemAt", + "builtin-fetchGit": "language/builtins.html#builtins-fetchGit", + "builtin-fetchTarball": "language/builtins.html#builtins-fetchTarball", + "builtin-fetchurl": "language/builtins.html#builtins-fetchurl", + "builtin-filterSource": "language/builtins.html#builtins-filterSource", + "builtin-foldl-prime": "language/builtins.html#builtins-foldl-prime", + "builtin-fromJSON": "language/builtins.html#builtins-fromJSON", + "builtin-functionArgs": "language/builtins.html#builtins-functionArgs", + "builtin-genList": "language/builtins.html#builtins-genList", + "builtin-getAttr": "language/builtins.html#builtins-getAttr", + "builtin-getEnv": "language/builtins.html#builtins-getEnv", + "builtin-hasAttr": "language/builtins.html#builtins-hasAttr", + "builtin-hashFile": "language/builtins.html#builtins-hashFile", + "builtin-hashString": "language/builtins.html#builtins-hashString", + "builtin-head": "language/builtins.html#builtins-head", + "builtin-import": "language/builtins.html#builtins-import", + "builtin-intersectAttrs": "language/builtins.html#builtins-intersectAttrs", + "builtin-isAttrs": "language/builtins.html#builtins-isAttrs", + "builtin-isBool": "language/builtins.html#builtins-isBool", + "builtin-isFloat": "language/builtins.html#builtins-isFloat", + "builtin-isFunction": "language/builtins.html#builtins-isFunction", + "builtin-isInt": "language/builtins.html#builtins-isInt", + "builtin-isList": "language/builtins.html#builtins-isList", + "builtin-isNull": "language/builtins.html#builtins-isNull", + "builtin-isString": "language/builtins.html#builtins-isString", + "builtin-length": "language/builtins.html#builtins-length", + "builtin-lessThan": "language/builtins.html#builtins-lessThan", + "builtin-listToAttrs": "language/builtins.html#builtins-listToAttrs", + "builtin-map": "language/builtins.html#builtins-map", + "builtin-match": "language/builtins.html#builtins-match", + "builtin-mul": "language/builtins.html#builtins-mul", + "builtin-parseDrvName": "language/builtins.html#builtins-parseDrvName", + "builtin-path": "language/builtins.html#builtins-path", + "builtin-pathExists": "language/builtins.html#builtins-pathExists", + "builtin-placeholder": "language/builtins.html#builtins-placeholder", + "builtin-readDir": "language/builtins.html#builtins-readDir", + "builtin-readFile": "language/builtins.html#builtins-readFile", + "builtin-removeAttrs": "language/builtins.html#builtins-removeAttrs", + "builtin-replaceStrings": "language/builtins.html#builtins-replaceStrings", + "builtin-seq": "language/builtins.html#builtins-seq", + "builtin-sort": "language/builtins.html#builtins-sort", + "builtin-split": "language/builtins.html#builtins-split", + "builtin-splitVersion": "language/builtins.html#builtins-splitVersion", + "builtin-stringLength": "language/builtins.html#builtins-stringLength", + "builtin-sub": "language/builtins.html#builtins-sub", + "builtin-substring": "language/builtins.html#builtins-substring", + "builtin-tail": "language/builtins.html#builtins-tail", + "builtin-throw": "language/builtins.html#builtins-throw", + "builtin-toFile": "language/builtins.html#builtins-toFile", + "builtin-toJSON": "language/builtins.html#builtins-toJSON", + "builtin-toPath": "language/builtins.html#builtins-toPath", + "builtin-toString": "language/builtins.html#builtins-toString", + "builtin-toXML": "language/builtins.html#builtins-toXML", + "builtin-trace": "language/builtins.html#builtins-trace", + "builtin-tryEval": "language/builtins.html#builtins-tryEval", + "builtin-typeOf": "language/builtins.html#builtins-typeOf", + "ssec-builtins": "language/builtins.html", + "attr-system": "language/derivations.html#attr-system", + "ssec-derivation": "language/derivations.html", + "ch-expression-language": "language/index.html", + "sec-constructs": "language/constructs.html", + "sect-let-language": "language/constructs.html#let-language", + "ss-functions": "language/constructs.html#functions", + "sec-language-operators": "language/operators.html", + "table-operators": "language/operators.html", + "ssec-values": "language/values.html", + "gloss-closure": "glossary.html#gloss-closure", + "gloss-derivation": "glossary.html#gloss-derivation", + "gloss-deriver": "glossary.html#gloss-deriver", + "gloss-nar": "glossary.html#gloss-nar", + "gloss-output-path": "glossary.html#gloss-output-path", + "gloss-profile": "glossary.html#gloss-profile", + "gloss-reachable": "glossary.html#gloss-reachable", + "gloss-reference": "glossary.html#gloss-reference", + "gloss-substitute": "glossary.html#gloss-substitute", + "gloss-user-env": "glossary.html#gloss-user-env", + "gloss-validity": "glossary.html#gloss-validity", + "part-glossary": "glossary.html", + "sec-building-source": "installation/building-source.html", + "ch-env-variables": "installation/env-variables.html", + "sec-installer-proxy-settings": "installation/env-variables.html#proxy-environment-variables", + "sec-nix-ssl-cert-file": "installation/env-variables.html#nix_ssl_cert_file", + "sec-nix-ssl-cert-file-with-nix-daemon-and-macos": "installation/env-variables.html#nix_ssl_cert_file-with-macos-and-the-nix-daemon", + "chap-installation": "installation/installation.html", + "ch-installing-binary": "installation/installing-binary.html", + "sect-macos-installation": "installation/installing-binary.html#macos-installation", + "sect-macos-installation-change-store-prefix": "installation/installing-binary.html#macos-installation", + "sect-macos-installation-encrypted-volume": "installation/installing-binary.html#macos-installation", + "sect-macos-installation-recommended-notes": "installation/installing-binary.html#macos-installation", + "sect-macos-installation-symlink": "installation/installing-binary.html#macos-installation", + "sect-multi-user-installation": "installation/installing-binary.html#multi-user-installation", + "sect-nix-install-binary-tarball": "installation/installing-binary.html#installing-from-a-binary-tarball", + "sect-nix-install-pinned-version-url": "installation/installing-binary.html#installing-a-pinned-nix-version-from-a-url", + "sect-single-user-installation": "installation/installing-binary.html#single-user-installation", + "ch-installing-source": "installation/installing-source.html", + "ssec-multi-user": "installation/multi-user.html", + "ch-nix-security": "installation/nix-security.html", + "sec-obtaining-source": "installation/obtaining-source.html", + "sec-prerequisites-source": "installation/prerequisites-source.html", + "sec-single-user": "installation/single-user.html", + "ch-supported-platforms": "installation/supported-platforms.html", + "ch-upgrading-nix": "installation/upgrading.html", + "ch-about-nix": "introduction.html", + "chap-introduction": "introduction.html", + "ch-basic-package-mgmt": "package-management/basic-package-mgmt.html", + "ssec-binary-cache-substituter": "package-management/binary-cache-substituter.html", + "sec-channels": "package-management/channels.html", + "ssec-copy-closure": "package-management/copy-closure.html", + "sec-garbage-collection": "package-management/garbage-collection.html", + "ssec-gc-roots": "package-management/garbage-collector-roots.html", + "chap-package-management": "package-management/package-management.html", + "sec-profiles": "package-management/profiles.html", + "ssec-s3-substituter": "package-management/s3-substituter.html", + "ssec-s3-substituter-anonymous-reads": "package-management/s3-substituter.html#anonymous-reads-to-your-s3-compatible-binary-cache", + "ssec-s3-substituter-authenticated-reads": "package-management/s3-substituter.html#authenticated-reads-to-your-s3-binary-cache", + "ssec-s3-substituter-authenticated-writes": "package-management/s3-substituter.html#authenticated-writes-to-your-s3-compatible-binary-cache", + "sec-sharing-packages": "package-management/sharing-packages.html", + "ssec-ssh-substituter": "package-management/ssh-substituter.html", + "chap-quick-start": "quick-start.html", + "sec-relnotes": "release-notes/release-notes.html", + "ch-relnotes-0.10.1": "release-notes/rl-0.10.1.html", + "ch-relnotes-0.10": "release-notes/rl-0.10.html", + "ssec-relnotes-0.11": "release-notes/rl-0.11.html", + "ssec-relnotes-0.12": "release-notes/rl-0.12.html", + "ssec-relnotes-0.13": "release-notes/rl-0.13.html", + "ssec-relnotes-0.14": "release-notes/rl-0.14.html", + "ssec-relnotes-0.15": "release-notes/rl-0.15.html", + "ssec-relnotes-0.16": "release-notes/rl-0.16.html", + "ch-relnotes-0.5": "release-notes/rl-0.5.html", + "ch-relnotes-0.6": "release-notes/rl-0.6.html", + "ch-relnotes-0.7": "release-notes/rl-0.7.html", + "ch-relnotes-0.8.1": "release-notes/rl-0.8.1.html", + "ch-relnotes-0.8": "release-notes/rl-0.8.html", + "ch-relnotes-0.9.1": "release-notes/rl-0.9.1.html", + "ch-relnotes-0.9.2": "release-notes/rl-0.9.2.html", + "ch-relnotes-0.9": "release-notes/rl-0.9.html", + "ssec-relnotes-1.0": "release-notes/rl-1.0.html", + "ssec-relnotes-1.1": "release-notes/rl-1.1.html", + "ssec-relnotes-1.10": "release-notes/rl-1.10.html", + "ssec-relnotes-1.11.10": "release-notes/rl-1.11.10.html", + "ssec-relnotes-1.11": "release-notes/rl-1.11.html", + "ssec-relnotes-1.2": "release-notes/rl-1.2.html", + "ssec-relnotes-1.3": "release-notes/rl-1.3.html", + "ssec-relnotes-1.4": "release-notes/rl-1.4.html", + "ssec-relnotes-1.5.1": "release-notes/rl-1.5.1.html", + "ssec-relnotes-1.5.2": "release-notes/rl-1.5.2.html", + "ssec-relnotes-1.5": "release-notes/rl-1.5.html", + "ssec-relnotes-1.6.1": "release-notes/rl-1.6.1.html", + "ssec-relnotes-1.6.0": "release-notes/rl-1.6.html", + "ssec-relnotes-1.7": "release-notes/rl-1.7.html", + "ssec-relnotes-1.8": "release-notes/rl-1.8.html", + "ssec-relnotes-1.9": "release-notes/rl-1.9.html", + "ssec-relnotes-2.0": "release-notes/rl-2.0.html", + "ssec-relnotes-2.1": "release-notes/rl-2.1.html", + "ssec-relnotes-2.2": "release-notes/rl-2.2.html", + "ssec-relnotes-2.3": "release-notes/rl-2.3.html" + }, + "language/values.html": { + "simple-values": "#primitives", + "lists": "#list", + "strings": "#string", + "lists": "#list", + "attribute-sets": "#attribute-set" + } +}; + +// the following code matches the current page's URL against the set of redirects. +// +// it is written to minimize the latency between page load and redirect. +// therefore we avoid function calls, copying data, and unnecessary loops. +// IMPORTANT: we use stateful array operations and their order matters! +// +// matching URLs is more involved than it should be: +// +// 1. `document.location.pathname` can have an arbitrary prefix. +// +// 2. `path_to_root` is set by mdBook. it consists only of `../`s and +// determines the depth of `<path>` relative to the prefix: +// +// `document.location.pathname` +// |------------------------------| +// /<prefix>/<path>/[<file>[.html]][#<anchor>] +// |----| +// `path_to_root` has same number of path segments +// +// source: https://phaiax.github.io/mdBook/format/theme/index-hbs.html#data +// +// 3. the following paths are equivalent: +// +// /foo/bar/ +// /foo/bar/index.html +// /foo/bar/index +// +// 4. the following paths are also equivalent: +// +// /foo/bar/baz +// /foo/bar/baz.html +// + +let segments = document.location.pathname.split('/'); + +let file = segments.pop(); + +// normalize file name +if (file === '') { file = "index.html"; } +else if (!file.endsWith('.html')) { file = file + '.html'; } + +segments.push(file); + +// use `path_to_root` to discern prefix from path. +const depth = path_to_root.split('/').length; + +// remove segments containing prefix. the following works because +// 1. the original `document.location.pathname` is absolute, +// hence first element of `segments` is always empty. +// 2. last element of splitting `path_to_root` is also always empty. +// 3. last element of `segments` is the file name. +// +// visual example: +// +// '/foo/bar/baz.html'.split('/') -> [ '', 'foo', 'bar', 'baz.html' ] +// '../'.split('/') -> [ '..', '' ] +// +// the following operations will then result in +// +// path = 'bar/baz.html' +// +segments.splice(0, segments.length - depth); +const path = segments.join('/'); + +// anchor starts with the hash character (`#`), +// but our redirect declarations don't, so we strip it. +// example: +// document.location.hash -> '#foo' +// document.location.hash.substring(1) -> 'foo' +const anchor = document.location.hash.substring(1); + +const redirect = redirects[path]; +if (redirect) { + const target = redirect[anchor]; + if (target) { + document.location.href = target; + } +} diff --git a/doc/manual/src/SUMMARY.md.in b/doc/manual/src/SUMMARY.md.in index 860222337..4f1fc34ce 100644 --- a/doc/manual/src/SUMMARY.md.in +++ b/doc/manual/src/SUMMARY.md.in @@ -26,21 +26,15 @@ - [Copying Closures via SSH](package-management/copy-closure.md) - [Serving a Nix store via SSH](package-management/ssh-substituter.md) - [Serving a Nix store via S3](package-management/s3-substituter.md) -- [Writing Nix Expressions](expressions/writing-nix-expressions.md) - - [A Simple Nix Expression](expressions/simple-expression.md) - - [Expression Syntax](expressions/expression-syntax.md) - - [Build Script](expressions/build-script.md) - - [Arguments and Variables](expressions/arguments-variables.md) - - [Building and Testing](expressions/simple-building-testing.md) - - [Generic Builder Syntax](expressions/generic-builder.md) - - [Writing Nix Expressions](expressions/expression-language.md) - - [Values](expressions/language-values.md) - - [Language Constructs](expressions/language-constructs.md) - - [Operators](expressions/language-operators.md) - - [Derivations](expressions/derivations.md) - - [Advanced Attributes](expressions/advanced-attributes.md) - - [Built-in Constants](expressions/builtin-constants.md) - - [Built-in Functions](expressions/builtins.md) +- [Nix Language](language/index.md) + - [Data Types](language/values.md) + - [Language Constructs](language/constructs.md) + - [String interpolation](language/string-interpolation.md) + - [Operators](language/operators.md) + - [Derivations](language/derivations.md) + - [Advanced Attributes](language/advanced-attributes.md) + - [Built-in Constants](language/builtin-constants.md) + - [Built-in Functions](language/builtins.md) - [Advanced Topics](advanced-topics/advanced-topics.md) - [Remote Builds](advanced-topics/distributed-builds.md) - [Tuning Cores and Jobs](advanced-topics/cores-vs-jobs.md) @@ -66,12 +60,17 @@ @manpages@ - [Files](command-ref/files.md) - [nix.conf](command-ref/conf-file.md) +- [Architecture](architecture/architecture.md) - [Glossary](glossary.md) - [Contributing](contributing/contributing.md) - [Hacking](contributing/hacking.md) - [CLI guideline](contributing/cli-guideline.md) - [Release Notes](release-notes/release-notes.md) - [Release X.Y (202?-??-??)](release-notes/rl-next.md) + - [Release 2.12 (2022-12-06)](release-notes/rl-2.12.md) + - [Release 2.11 (2022-08-25)](release-notes/rl-2.11.md) + - [Release 2.10 (2022-07-11)](release-notes/rl-2.10.md) + - [Release 2.9 (2022-05-30)](release-notes/rl-2.9.md) - [Release 2.8 (2022-04-19)](release-notes/rl-2.8.md) - [Release 2.7 (2022-03-07)](release-notes/rl-2.7.md) - [Release 2.6 (2022-01-24)](release-notes/rl-2.6.md) diff --git a/doc/manual/src/advanced-topics/diff-hook.md b/doc/manual/src/advanced-topics/diff-hook.md index 7a2622b3d..4a742c160 100644 --- a/doc/manual/src/advanced-topics/diff-hook.md +++ b/doc/manual/src/advanced-topics/diff-hook.md @@ -101,7 +101,7 @@ In particular, notice the `/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable.check` output. Nix has copied the build results to that directory where you can examine it. -> **Note** +> []{#check-dirs-are-unregistered} **Note** > > Check paths are not protected against garbage collection, and this > path will be deleted on the next garbage collection. @@ -121,37 +121,3 @@ error: are not valid, so checking is not possible Run the build without `--check`, and then try with `--check` again. - -# Automatic and Optionally Enforced Determinism Verification - -Automatically verify every build at build time by executing the build -multiple times. - -Setting `repeat` and `enforce-determinism` in your `nix.conf` permits -the automated verification of every build Nix performs. - -The following configuration will run each build three times, and will -require the build to be deterministic: - - enforce-determinism = true - repeat = 2 - -Setting `enforce-determinism` to false as in the following -configuration will run the build multiple times, execute the build -hook, but will allow the build to succeed even if it does not build -reproducibly: - - enforce-determinism = false - repeat = 1 - -An example output of this configuration: - -```console -$ nix-build ./test.nix -A unstable -this derivation will be built: - /nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv -building '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' (round 1/2)... -building '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' (round 2/2)... -output '/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable' of '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' differs from '/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable.check' from previous round -/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable -``` diff --git a/doc/manual/src/advanced-topics/distributed-builds.md b/doc/manual/src/advanced-topics/distributed-builds.md index b0d7fbf1a..fefd10100 100644 --- a/doc/manual/src/advanced-topics/distributed-builds.md +++ b/doc/manual/src/advanced-topics/distributed-builds.md @@ -12,14 +12,14 @@ machine is accessible via SSH and that it has Nix installed. You can test whether connecting to the remote Nix instance works, e.g. ```console -$ nix ping-store --store ssh://mac +$ nix store ping --store ssh://mac ``` will try to connect to the machine named `mac`. It is possible to specify an SSH identity file as part of the remote store URI, e.g. ```console -$ nix ping-store --store ssh://mac?ssh-key=/home/alice/my-key +$ nix store ping --store ssh://mac?ssh-key=/home/alice/my-key ``` Since builds should be non-interactive, the key should not have a diff --git a/doc/manual/src/advanced-topics/post-build-hook.md b/doc/manual/src/advanced-topics/post-build-hook.md index fcb52d878..1479cc3a4 100644 --- a/doc/manual/src/advanced-topics/post-build-hook.md +++ b/doc/manual/src/advanced-topics/post-build-hook.md @@ -33,12 +33,17 @@ distribute the public key for verifying the authenticity of the paths. example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM= ``` -Then, add the public key and the cache URL to your `nix.conf`'s -`trusted-public-keys` and `substituters` options: +Then update [`nix.conf`](../command-ref/conf-file.md) on any machine that will access the cache. +Add the cache URL to [`substituters`](../command-ref/conf-file.md#conf-substituters) and the public key to [`trusted-public-keys`](../command-ref/conf-file.md#conf-trusted-public-keys): substituters = https://cache.nixos.org/ s3://example-nix-cache trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM= +Machines that build for the cache must sign derivations using the private key. +On those machines, add the path to the key file to the [`secret-key-files`](../command-ref/conf-file.md#conf-secret-key-files) field in their [`nix.conf`](../command-ref/conf-file.md): + + secret-key-files = /etc/nix/key.private + We will restart the Nix daemon in a later step. # Implementing the build hook @@ -52,14 +57,12 @@ set -eu set -f # disable globbing export IFS=' ' -echo "Signing paths" $OUT_PATHS -nix store sign --key-file /etc/nix/key.private $OUT_PATHS echo "Uploading paths" $OUT_PATHS -exec nix copy --to 's3://example-nix-cache' $OUT_PATHS +exec nix copy --to "s3://example-nix-cache" $OUT_PATHS ``` > **Note** -> +> > The `$OUT_PATHS` variable is a space-separated list of Nix store > paths. In this case, we expect and want the shell to perform word > splitting to make each output path its own argument to `nix diff --git a/doc/manual/src/architecture/architecture.md b/doc/manual/src/architecture/architecture.md new file mode 100644 index 000000000..2d1b26558 --- /dev/null +++ b/doc/manual/src/architecture/architecture.md @@ -0,0 +1,115 @@ +# Architecture + +This chapter describes how Nix works. +It should help users understand why Nix behaves as it does, and it should help developers understand how to modify Nix and how to write similar tools. + +## Overview + +Nix consists of [hierarchical layers]. + +[hierarchical layers]: https://en.m.wikipedia.org/wiki/Multitier_architecture#Layers + +The following [concept map] shows its main components (rectangles), the objects they operate on (rounded rectangles), and their interactions (connecting phrases): + +[concept map]: https://en.m.wikipedia.org/wiki/Concept_map + +``` + + .----------------. + | Nix expression |----------. + '----------------' | + | passed to + | | ++----------|-------------------|--------------------------------+ +| Nix | V | +| | +-------------------------+ | +| | | commmand line interface |------. | +| | +-------------------------+ | | +| | | | | +| evaluated by calls manages | +| | | | | +| | V | | +| | +--------------------+ | | +| '-------->| language evaluator | | | +| +--------------------+ | | +| | | | +| produces | | +| | V | +| +----------------------------|------------------------------+ | +| | store | | | +| | referenced by V builds | | +| | .-------------. .------------. .--------------. | | +| | | build input |----->| build plan |----->| build result | | | +| | '-------------' '------------' '--------------' | | +| +-------------------------------------------------|---------+ | ++---------------------------------------------------|-----------+ + | + represented as + | + V + .---------------. + | file | + '---------------' +``` + +At the top is the [command line interface](../command-ref/command-ref.md) that drives the underlying layers. + +The [Nix language](../language/index.md) evaluator transforms Nix expressions into self-contained *build plans*, which are used to derive *build results* from referenced *build inputs*. + +The command line interface and Nix expressions are what users deal with most. + +> **Note** +> The Nix language itself does not have a notion of *packages* or *configurations*. +> As far as we are concerned here, the inputs and results of a build plan are just data. + +Underlying the command line interface and the Nix language evaluator is the [Nix store](../glossary.md#gloss-store), a mechanism to keep track of build plans, data, and references between them. +It can also execute build plans to produce new data, which are made available to the operating system as files. + +A build plan itself is a series of *build tasks*, together with their build inputs. + +> **Important** +> A build task in Nix is called [derivation](../glossary#gloss-derivation). + +Each build task has a special build input executed as *build instructions* in order to perform the build. +The result of a build task can be input to another build task. + +The following [data flow diagram] shows a build plan for illustration. +Build inputs used as instructions to a build task are marked accordingly: + +[data flow diagram]: https://en.m.wikipedia.org/wiki/Data-flow_diagram + +``` ++--------------------------------------------------------------------+ +| build plan | +| | +| .-------------. | +| | build input |---------. | +| '-------------' | | +| instructions | +| | | +| v | +| .-------------. .----------. | +| | build input |-->( build task )-------. | +| '-------------' '----------' | | +| instructions | +| | | +| v | +| .-------------. .----------. .--------------. | +| | build input |---------. ( build task )--->| build result | | +| '-------------' | '----------' '--------------' | +| instructions ^ | +| | | | +| v | | +| .-------------. .----------. | | +| | build input |-->( build task )-------' | +| '-------------' '----------' | +| ^ | +| | | +| | | +| .-------------. | | +| | build input |---------' | +| '-------------' | +| | ++--------------------------------------------------------------------+ +``` + diff --git a/doc/manual/src/command-ref/env-common.md b/doc/manual/src/command-ref/env-common.md index 6e2403461..5845bdc43 100644 --- a/doc/manual/src/command-ref/env-common.md +++ b/doc/manual/src/command-ref/env-common.md @@ -2,49 +2,18 @@ Most Nix commands interpret the following environment variables: - - `IN_NIX_SHELL`\ + - [`IN_NIX_SHELL`]{#env-IN_NIX_SHELL}\ Indicator that tells if the current environment was set up by - `nix-shell`. Since Nix 2.0 the values are `"pure"` and `"impure"` + `nix-shell`. It can have the values `pure` or `impure`. - - `NIX_PATH`\ - A colon-separated list of directories used to look up Nix - expressions enclosed in angle brackets (i.e., `<path>`). For - instance, the value + - [`NIX_PATH`]{#env-NIX_PATH}\ + A colon-separated list of directories used to look up the location of Nix + expressions using [paths](../language/values.md#type-path) + enclosed in angle brackets (i.e., `<path>`), + e.g. `/home/eelco/Dev:/etc/nixos`. It can be extended using the + [`-I` option](./opt-common#opt-I). - /home/eelco/Dev:/etc/nixos - - will cause Nix to look for paths relative to `/home/eelco/Dev` and - `/etc/nixos`, in this order. It is also possible to match paths - against a prefix. For example, the value - - nixpkgs=/home/eelco/Dev/nixpkgs-branch:/etc/nixos - - will cause Nix to search for `<nixpkgs/path>` in - `/home/eelco/Dev/nixpkgs-branch/path` and `/etc/nixos/nixpkgs/path`. - - If a path in the Nix search path starts with `http://` or - `https://`, it is interpreted as the URL of a tarball that will be - downloaded and unpacked to a temporary location. The tarball must - consist of a single top-level directory. For example, setting - `NIX_PATH` to - - nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz - - tells Nix to download and use the current contents of the - `master` branch in the `nixpkgs` repository. - - The URLs of the tarballs from the official nixos.org channels (see - [the manual for `nix-channel`](nix-channel.md)) can be abbreviated - as `channel:<channel-name>`. For instance, the following two - values of `NIX_PATH` are equivalent: - - nixpkgs=channel:nixos-21.05 - nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz - - The Nix search path can also be extended using the `-I` option to - many Nix commands, which takes precedence over `NIX_PATH`. - - - `NIX_IGNORE_SYMLINK_STORE`\ + - [`NIX_IGNORE_SYMLINK_STORE`]{#env-NIX_IGNORE_SYMLINK_STORE}\ Normally, the Nix store directory (typically `/nix/store`) is not allowed to contain any symlink components. This is to prevent “impure” builds. Builders sometimes “canonicalise” paths by @@ -66,41 +35,41 @@ Most Nix commands interpret the following environment variables: Consult the mount 8 manual page for details. - - `NIX_STORE_DIR`\ + - [`NIX_STORE_DIR`]{#env-NIX_STORE_DIR}\ Overrides the location of the Nix store (default `prefix/store`). - - `NIX_DATA_DIR`\ + - [`NIX_DATA_DIR`]{#env-NIX_DATA_DIR}\ Overrides the location of the Nix static data directory (default `prefix/share`). - - `NIX_LOG_DIR`\ + - [`NIX_LOG_DIR`]{#env-NIX_LOG_DIR}\ Overrides the location of the Nix log directory (default `prefix/var/log/nix`). - - `NIX_STATE_DIR`\ + - [`NIX_STATE_DIR`]{#env-NIX_STATE_DIR}\ Overrides the location of the Nix state directory (default `prefix/var/nix`). - - `NIX_CONF_DIR`\ + - [`NIX_CONF_DIR`]{#env-NIX_CONF_DIR}\ Overrides the location of the system Nix configuration directory (default `prefix/etc/nix`). - - `NIX_CONFIG`\ + - [`NIX_CONFIG`]{#env-NIX_CONFIG}\ Applies settings from Nix configuration from the environment. The content is treated as if it was read from a Nix configuration file. Settings are separated by the newline character. - - `NIX_USER_CONF_FILES`\ + - [`NIX_USER_CONF_FILES`]{#env-NIX_USER_CONF_FILES}\ Overrides the location of the user Nix configuration files to load from (defaults to the XDG spec locations). The variable is treated as a list separated by the `:` token. - - `TMPDIR`\ + - [`TMPDIR`]{#env-TMPDIR}\ Use the specified directory to store temporary files. In particular, this includes temporary build directories; these can take up substantial amounts of disk space. The default is `/tmp`. - - `NIX_REMOTE`\ + - [`NIX_REMOTE`]{#env-NIX_REMOTE}\ This variable should be set to `daemon` if you want to use the Nix daemon to execute Nix operations. This is necessary in [multi-user Nix installations](../installation/multi-user.md). If the Nix @@ -108,16 +77,16 @@ Most Nix commands interpret the following environment variables: should be set to `unix://path/to/socket`. Otherwise, it should be left unset. - - `NIX_SHOW_STATS`\ + - [`NIX_SHOW_STATS`]{#env-NIX_SHOW_STATS}\ If set to `1`, Nix will print some evaluation statistics, such as the number of values allocated. - - `NIX_COUNT_CALLS`\ + - [`NIX_COUNT_CALLS`]{#env-NIX_COUNT_CALLS}\ If set to `1`, Nix will print how often functions were called during Nix expression evaluation. This is useful for profiling your Nix expressions. - - `GC_INITIAL_HEAP_SIZE`\ + - [`GC_INITIAL_HEAP_SIZE`]{#env-GC_INITIAL_HEAP_SIZE}\ If Nix has been configured to use the Boehm garbage collector, this variable sets the initial size of the heap in bytes. It defaults to 384 MiB. Setting it to a low value reduces memory consumption, but diff --git a/doc/manual/src/command-ref/nix-build.md b/doc/manual/src/command-ref/nix-build.md index 43de7a6e6..937b046b8 100644 --- a/doc/manual/src/command-ref/nix-build.md +++ b/doc/manual/src/command-ref/nix-build.md @@ -12,6 +12,12 @@ [`--dry-run`] [{`--out-link` | `-o`} *outlink*] +# Disambiguation + +This man page describes the command `nix-build`, which is distinct from `nix +build`. For documentation on the latter, run `nix build --help` or see `man +nix3-build`. + # Description The `nix-build` command builds the derivations described by the Nix @@ -31,10 +37,12 @@ directory containing at least a file named `default.nix`. `nix-build` is essentially a wrapper around [`nix-instantiate`](nix-instantiate.md) (to translate a high-level Nix -expression to a low-level store derivation) and [`nix-store +expression to a low-level [store derivation]) and [`nix-store --realise`](nix-store.md#operation---realise) (to build the store derivation). +[store derivation]: ../glossary.md#gloss-store-derivation + > **Warning** > > The result of the build is automatically registered as a root of the @@ -47,16 +55,18 @@ All options not listed here are passed to `nix-store --realise`, except for `--arg` and `--attr` / `-A` which are passed to `nix-instantiate`. - - `--no-out-link`\ + - <span id="opt-no-out-link">[`--no-out-link`](#opt-no-out-link)<span> + Do not create a symlink to the output path. Note that as a result the output does not become a root of the garbage collector, and so - might be deleted by `nix-store - --gc`. + might be deleted by `nix-store --gc`. + + - <span id="opt-dry-run">[`--dry-run`](#opt-dry-run)</span> - - `--dry-run`\ Show what store paths would be built or downloaded. - - `--out-link` / `-o` *outlink*\ + - <span id="opt-out-link">[`--out-link`](#opt-out-link)</span> / `-o` *outlink* + Change the name of the symlink to the output path created from `result` to *outlink*. diff --git a/doc/manual/src/command-ref/nix-copy-closure.md b/doc/manual/src/command-ref/nix-copy-closure.md index 7047d3012..83e8a2936 100644 --- a/doc/manual/src/command-ref/nix-copy-closure.md +++ b/doc/manual/src/command-ref/nix-copy-closure.md @@ -30,8 +30,8 @@ Since `nix-copy-closure` calls `ssh`, you may be asked to type in the appropriate password or passphrase. In fact, you may be asked _twice_ because `nix-copy-closure` currently connects twice to the remote machine, first to get the set of paths missing on the target machine, -and second to send the dump of those paths. If this bothers you, use -`ssh-agent`. +and second to send the dump of those paths. When using public key +authentication, you can avoid typing the passphrase with `ssh-agent`. # Options @@ -47,7 +47,9 @@ and second to send the dump of those paths. If this bothers you, use Enable compression of the SSH connection. - `--include-outputs`\ - Also copy the outputs of store derivations included in the closure. + Also copy the outputs of [store derivation]s included in the closure. + + [store derivation]: ../../glossary.md#gloss-store-derivation - `--use-substitutes` / `-s`\ Attempt to download missing paths on the target machine using Nix’s diff --git a/doc/manual/src/command-ref/nix-daemon.md b/doc/manual/src/command-ref/nix-daemon.md index e91cb01dd..04b483be3 100644 --- a/doc/manual/src/command-ref/nix-daemon.md +++ b/doc/manual/src/command-ref/nix-daemon.md @@ -8,6 +8,6 @@ # Description -The Nix daemon is necessary in multi-user Nix installations. It performs -build actions and other operations on the Nix store on behalf of +The Nix daemon is necessary in multi-user Nix installations. It runs +build tasks and other operations on the Nix store on behalf of unprivileged users. diff --git a/doc/manual/src/command-ref/nix-env.md b/doc/manual/src/command-ref/nix-env.md index 8d6abaf52..f4fa5b50c 100644 --- a/doc/manual/src/command-ref/nix-env.md +++ b/doc/manual/src/command-ref/nix-env.md @@ -31,7 +31,7 @@ subcommand to be performed. These are documented below. Several commands, such as `nix-env -q` and `nix-env -i`, take a list of arguments that specify the packages on which to operate. These are extended regular expressions that must match the entire name of the -package. (For details on regular expressions, see regex7.) The match is +package. (For details on regular expressions, see **regex**(7).) The match is case-sensitive. The regular expression can optionally be followed by a dash and a version number; if omitted, any version of the package will match. Here are some examples: @@ -198,17 +198,19 @@ a number of possible ways: another. - If `--from-expression` is given, *args* are Nix - [functions](../expressions/language-constructs.md#functions) + [functions](../language/constructs.md#functions) that are called with the active Nix expression as their single argument. The derivations returned by those function calls are installed. This allows derivations to be specified in an unambiguous way, which is necessary if there are multiple derivations with the same name. - - If *args* are store derivations, then these are + - If *args* are [store derivation]s, then these are [realised](nix-store.md#operation---realise), and the resulting output paths are installed. + [store derivation]: ../glossary.md#gloss-store-derivation + - If *args* are store paths that are not store derivations, then these are [realised](nix-store.md#operation---realise) and installed. @@ -280,7 +282,7 @@ To copy the store path with symbolic name `gcc` from another profile: $ nix-env -i --from-profile /nix/var/nix/profiles/foo gcc ``` -To install a specific store derivation (typically created by +To install a specific [store derivation] (typically created by `nix-instantiate`): ```console @@ -412,7 +414,7 @@ The upgrade operation determines whether a derivation `y` is an upgrade of a derivation `x` by looking at their respective `name` attributes. The names (e.g., `gcc-3.3.1` are split into two parts: the package name (`gcc`), and the version (`3.3.1`). The version part starts after the -first dash not followed by a letter. `x` is considered an upgrade of `y` +first dash not followed by a letter. `y` is considered an upgrade of `x` if their package names match, and the version of `y` is higher than that of `x`. @@ -665,7 +667,7 @@ derivation is shown unless `--no-name` is specified. Print the `system` attribute of the derivation. - `--drv-path`\ - Print the path of the store derivation. + Print the path of the [store derivation]. - `--out-path`\ Print the output path of the derivation. diff --git a/doc/manual/src/command-ref/nix-instantiate.md b/doc/manual/src/command-ref/nix-instantiate.md index 2e198daed..432fb2608 100644 --- a/doc/manual/src/command-ref/nix-instantiate.md +++ b/doc/manual/src/command-ref/nix-instantiate.md @@ -17,13 +17,14 @@ # Description -The command `nix-instantiate` generates [store -derivations](../glossary.md) from (high-level) Nix expressions. It -evaluates the Nix expressions in each of *files* (which defaults to +The command `nix-instantiate` produces [store derivation]s from (high-level) Nix expressions. +It evaluates the Nix expressions in each of *files* (which defaults to *./default.nix*). Each top-level expression should evaluate to a derivation, a list of derivations, or a set of derivations. The paths of the resulting store derivations are printed on standard output. +[store derivation]: ../glossary.md#gloss-store-derivation + If *files* is the character `-`, then a Nix expression will be read from standard input. @@ -51,7 +52,7 @@ standard input. - `--strict`\ When used with `--eval`, recursively evaluate list elements and attributes. Normally, such sub-expressions are left unevaluated - (since the Nix expression language is lazy). + (since the Nix language is lazy). > **Warning** > @@ -66,7 +67,7 @@ standard input. When used with `--eval`, print the resulting value as an XML representation of the abstract syntax tree rather than as an ATerm. The schema is the same as that used by the [`toXML` - built-in](../expressions/builtins.md). + built-in](../language/builtins.md). - `--read-write-mode`\ When used with `--eval`, perform evaluation in read/write mode so @@ -79,8 +80,7 @@ standard input. # Examples -Instantiating store derivations from a Nix expression, and building them -using `nix-store`: +Instantiate [store derivation]s from a Nix expression, and build them using `nix-store`: ```console $ nix-instantiate test.nix (instantiate) diff --git a/doc/manual/src/command-ref/nix-shell.md b/doc/manual/src/command-ref/nix-shell.md index a2b6d8a8e..840bccd25 100644 --- a/doc/manual/src/command-ref/nix-shell.md +++ b/doc/manual/src/command-ref/nix-shell.md @@ -15,6 +15,12 @@ [`--keep` *name*] {{`--packages` | `-p`} {*packages* | *expressions*} … | [*path*]} +# Disambiguation + +This man page describes the command `nix-shell`, which is distinct from `nix +shell`. For documentation on the latter, run `nix shell --help` or see `man +nix3-shell`. + # Description The command `nix-shell` will build the dependencies of the specified diff --git a/doc/manual/src/command-ref/nix-store.md b/doc/manual/src/command-ref/nix-store.md index 7db9f0c1c..acf29e4aa 100644 --- a/doc/manual/src/command-ref/nix-store.md +++ b/doc/manual/src/command-ref/nix-store.md @@ -22,7 +22,8 @@ This section lists the options that are common to all operations. These options are allowed for every subcommand, though they may not always have an effect. - - `--add-root` *path*\ + - <span id="opt-add-root">[`--add-root`](#opt-add-root)</span> *path* + Causes the result of a realisation (`--realise` and `--force-realise`) to be registered as a root of the garbage collector. *path* will be created as a symlink to the resulting @@ -71,7 +72,7 @@ paths. Realisation is a somewhat overloaded term: outputs are already valid, in which case we are done immediately. Otherwise, there may be [substitutes](../glossary.md) that produce the outputs (e.g., by downloading them). Finally, the - outputs can be produced by performing the build action described + outputs can be produced by running the build task described by the derivation. - If the store path is not a derivation, realisation ensures that the @@ -104,10 +105,6 @@ The following flags are available: previous build, the new output path is left in `/nix/store/name.check.` - See also the `build-repeat` configuration option, which repeats a - derivation a number of times and prevents its outputs from being - registered as “valid” in the Nix store unless they are identical. - Special exit codes: - `100`\ @@ -121,7 +118,7 @@ Special exit codes: - `102`\ Hash mismatch, the build output was rejected because it does not match the [`outputHash` attribute of the - derivation](../expressions/advanced-attributes.md). + derivation](../language/advanced-attributes.md). - `104`\ Not deterministic, the build succeeded in check mode but the @@ -140,8 +137,10 @@ or. ## Examples -This operation is typically used to build store derivations produced by -[`nix-instantiate`](nix-instantiate.md): +This operation is typically used to build [store derivation]s produced by +[`nix-instantiate`](./nix-instantiate.md): + +[store derivation]: ../glossary.md#gloss-store-derivation ```console $ nix-store -r $(nix-instantiate ./test.nix) @@ -301,7 +300,7 @@ symlink. ## Common query options - `--use-output`; `-u`\ - For each argument to the query that is a store derivation, apply the + For each argument to the query that is a [store derivation], apply the query to the output path of the derivation instead. - `--force-realise`; `-f`\ @@ -321,7 +320,7 @@ symlink. This query has one option: - `--include-outputs` - Also include the existing output paths of store derivations, + Also include the existing output paths of [store derivation]s, and their closures. This query can be used to implement various kinds of deployment. A @@ -375,12 +374,12 @@ symlink. Prints the references graph of the store paths *paths* in the [GraphML](http://graphml.graphdrawing.org/) file format. This can be used to visualise dependency graphs. To obtain a build-time - dependency graph, apply this to a store derivation. To obtain a + dependency graph, apply this to a [store derivation]. To obtain a runtime dependency graph, apply it to an output path. - `--binding` *name*; `-b` *name*\ Prints the value of the attribute *name* (i.e., environment - variable) of the store derivations *paths*. It is an error for a + variable) of the [store derivation]s *paths*. It is an error for a derivation to not have the specified attribute. - `--hash`\ diff --git a/doc/manual/src/command-ref/opt-common.md b/doc/manual/src/command-ref/opt-common.md index 7ee1a26bc..e612c416f 100644 --- a/doc/manual/src/command-ref/opt-common.md +++ b/doc/manual/src/command-ref/opt-common.md @@ -2,13 +2,13 @@ Most Nix commands accept the following command-line options: - - `--help`\ + - [`--help`]{#opt-help}\ Prints out a summary of the command syntax and exits. - - `--version`\ + - [`--version`]{#opt-version}\ Prints out the Nix version number on standard output and exits. - - `--verbose` / `-v`\ + - [`--verbose`]{#opt-verbose} / `-v`\ Increases the level of verbosity of diagnostic messages printed on standard error. For each Nix operation, the information printed on standard output is well-defined; any diagnostic information is @@ -37,14 +37,14 @@ Most Nix commands accept the following command-line options: - 5\ “Vomit”: print vast amounts of debug information. - - `--quiet`\ + - [`--quiet`]{#opt-quiet}\ Decreases the level of verbosity of diagnostic messages printed on standard error. This is the inverse option to `-v` / `--verbose`. This option may be specified repeatedly. See the previous verbosity levels list. - - `--log-format` *format*\ + - [`--log-format`]{#opt-log-format} *format*\ This option can be used to change the output of the log format, with *format* being one of: @@ -66,14 +66,14 @@ Most Nix commands accept the following command-line options: - bar-with-logs\ Display the raw logs, with the progress bar at the bottom. - - `--no-build-output` / `-Q`\ + - [`--no-build-output`]{#opt-no-build-output} / `-Q`\ By default, output written by builders to standard output and standard error is echoed to the Nix command's standard error. This option suppresses this behaviour. Note that the builder's standard output and error are always written to a log file in `prefix/nix/var/log/nix`. - - `--max-jobs` / `-j` *number*\ + - [`--max-jobs`]{#opt-max-jobs} / `-j` *number*\ Sets the maximum number of build jobs that Nix will perform in parallel to the specified number. Specify `auto` to use the number of CPUs in the system. The default is specified by the `max-jobs` @@ -83,7 +83,7 @@ Most Nix commands accept the following command-line options: Setting it to `0` disallows building on the local machine, which is useful when you want builds to happen only on remote builders. - - `--cores`\ + - [`--cores`]{#opt-cores}\ Sets the value of the `NIX_BUILD_CORES` environment variable in the invocation of builders. Builders can use this variable at their discretion to control the maximum amount of parallelism. For @@ -94,18 +94,18 @@ Most Nix commands accept the following command-line options: means that the builder should use all available CPU cores in the system. - - `--max-silent-time`\ + - [`--max-silent-time`]{#opt-max-silent-time}\ Sets the maximum number of seconds that a builder can go without producing any data on standard output or standard error. The default is specified by the `max-silent-time` configuration setting. `0` means no time-out. - - `--timeout`\ + - [`--timeout`]{#opt-timeout}\ Sets the maximum number of seconds that a builder can run. The default is specified by the `timeout` configuration setting. `0` means no timeout. - - `--keep-going` / `-k`\ + - [`--keep-going`]{#opt-keep-going} / `-k`\ Keep going in case of failed builds, to the greatest extent possible. That is, if building an input of some derivation fails, Nix will still build the other inputs, but not the derivation @@ -113,13 +113,13 @@ Most Nix commands accept the following command-line options: for builds of substitutes), possibly killing builds in progress (in case of parallel or distributed builds). - - `--keep-failed` / `-K`\ + - [`--keep-failed`]{#opt-keep-failed} / `-K`\ Specifies that in case of a build failure, the temporary directory (usually in `/tmp`) in which the build takes place should not be deleted. The path of the build directory is printed as an informational message. - - `--fallback`\ + - [`--fallback`]{#opt-fallback}\ Whenever Nix attempts to build a derivation for which substitutes are known for each output path, but realising the output paths through the substitutes fails, fall back on building the derivation. @@ -134,18 +134,18 @@ Most Nix commands accept the following command-line options: failure in obtaining the substitutes to lead to a full build from source (with the related consumption of resources). - - `--readonly-mode`\ + - [`--readonly-mode`]{#opt-readonly-mode}\ When this option is used, no attempt is made to open the Nix database. Most Nix operations do need database access, so those operations will fail. - - `--arg` *name* *value*\ + - [`--arg`]{#opt-arg} *name* *value*\ This option is accepted by `nix-env`, `nix-instantiate`, `nix-shell` and `nix-build`. When evaluating Nix expressions, the expression evaluator will automatically try to call functions that it encounters. It can automatically call functions for which every argument has a [default - value](../expressions/language-constructs.md#functions) (e.g., + value](../language/constructs.md#functions) (e.g., `{ argName ? defaultValue }: ...`). With `--arg`, you can also call functions that have arguments without a default value (or override a default value). That is, if the evaluator encounters a @@ -164,19 +164,19 @@ Most Nix commands accept the following command-line options: So if you call this Nix expression (e.g., when you do `nix-env -iA pkgname`), the function will be called automatically using the - value [`builtins.currentSystem`](../expressions/builtins.md) for + value [`builtins.currentSystem`](../language/builtins.md) for the `system` argument. You can override this using `--arg`, e.g., `nix-env -iA pkgname --arg system \"i686-freebsd\"`. (Note that since the argument is a Nix string literal, you have to escape the quotes.) - - `--argstr` *name* *value*\ + - [`--argstr`]{#opt-argstr} *name* *value*\ This option is like `--arg`, only the value is not a Nix expression but a string. So instead of `--arg system \"i686-linux\"` (the outer quotes are to keep the shell happy) you can say `--argstr system i686-linux`. - - `--attr` / `-A` *attrPath*\ + - [`--attr`]{#opt-attr} / `-A` *attrPath*\ Select an attribute from the top-level Nix expression being evaluated. (`nix-env`, `nix-instantiate`, `nix-build` and `nix-shell` only.) The *attribute path* *attrPath* is a sequence @@ -191,7 +191,7 @@ Most Nix commands accept the following command-line options: attribute of the fourth element of the array in the `foo` attribute of the top-level expression. - - `--expr` / `-E`\ + - [`--expr`]{#opt-expr} / `-E`\ Interpret the command line arguments as a list of Nix expressions to be parsed and evaluated, rather than as a list of file names of Nix expressions. (`nix-instantiate`, `nix-build` and `nix-shell` only.) @@ -202,17 +202,17 @@ Most Nix commands accept the following command-line options: use, give your expression to the `nix-shell -p` convenience flag instead. - - `-I` *path*\ + - [`-I`]{#opt-I} *path*\ Add a path to the Nix expression search path. This option may be given multiple times. See the `NIX_PATH` environment variable for information on the semantics of the Nix search path. Paths added through `-I` take precedence over `NIX_PATH`. - - `--option` *name* *value*\ + - [`--option`]{#opt-option} *name* *value*\ Set the Nix configuration option *name* to *value*. This overrides settings in the Nix configuration file (see nix.conf5). - - `--repair`\ + - [`--repair`]{#opt-repair}\ Fix corrupted or missing store paths by redownloading or rebuilding them. Note that this is slow because it requires computing a cryptographic hash of the contents of every path in the closure of diff --git a/doc/manual/src/contributing/hacking.md b/doc/manual/src/contributing/hacking.md index 90a8f1f94..c9da1962f 100644 --- a/doc/manual/src/contributing/hacking.md +++ b/doc/manual/src/contributing/hacking.md @@ -42,7 +42,7 @@ $ nix develop ``` To get a shell with a different compilation environment (e.g. stdenv, -gccStdenv, clangStdenv, clang11Stdenv): +gccStdenv, clangStdenv, clang11Stdenv, ccacheStdenv): ```console $ nix-shell -A devShells.x86_64-linux.clang11StdenvPackages @@ -54,6 +54,9 @@ or if you have a flake-enabled nix: $ nix develop .#clang11StdenvPackages ``` +Note: you can use `ccacheStdenv` to drastically improve rebuild +time. By default, ccache keeps artifacts in `~/.cache/ccache/`. + To build Nix itself in this shell: ```console @@ -71,26 +74,178 @@ To install it in `$(pwd)/outputs` and test it: nix (Nix) 3.0 ``` -To run a functional test: +If you have a flakes-enabled Nix you can replace: ```console -make tests/test-name-should-auto-complete.sh.test +$ nix-shell ``` -To run the unit-tests for C++ code: +by: +```console +$ nix develop ``` -make check + +## Running tests + +### Unit-tests + +The unit-tests for each Nix library (`libexpr`, `libstore`, etc..) are defined +under `src/{library_name}/tests` using the +[googletest](https://google.github.io/googletest/) framework. + +You can run the whole testsuite with `make check`, or the tests for a specific component with `make libfoo-tests_RUN`. Finer-grained filtering is also possible using the [--gtest_filter](https://google.github.io/googletest/advanced.html#running-a-subset-of-the-tests) command-line option. + +### Functional tests + +The functional tests reside under the `tests` directory and are listed in `tests/local.mk`. +Each test is a bash script. + +The whole test suite can be run with: + +```shell-session +$ make install && make installcheck +ran test tests/foo.sh... [PASS] +ran test tests/bar.sh... [PASS] +... ``` -If you have a flakes-enabled Nix you can replace: +Individual tests can be run with `make`: -```console -$ nix-shell +```shell-session +$ make tests/${testName}.sh.test +ran test tests/${testName}.sh... [PASS] ``` -by: +or without `make`: -```console -$ nix develop +```shell-session +$ ./mk/run-test.sh tests/${testName}.sh +ran test tests/${testName}.sh... [PASS] +``` + +To see the complete output, one can also run: + +```shell-session +$ ./mk/debug-test.sh tests/${testName}.sh ++ foo +output from foo ++ bar +output from bar +... ``` + +The test script will then be traced with `set -x` and the output displayed as it happens, regardless of whether the test succeeds or fails. + +#### Debugging failing functional tests + +When a functional test fails, it usually does so somewhere in the middle of the script. + +To figure out what's wrong, it is convenient to run the test regularly up to the failing `nix` command, and then run that command with a debugger like GDB. + +For example, if the script looks like: + +```bash +foo +nix blah blub +bar +``` +edit it like so: + +```diff + foo +-nix blah blub ++gdb --args nix blah blub + bar +``` + +Then, running the test with `./mk/debug-test.sh` will drop you into GDB once the script reaches that point: + +```shell-session +$ ./mk/debug-test.sh tests/${testName}.sh +... ++ gdb blash blub +GNU gdb (GDB) 12.1 +... +(gdb) +``` + +One can debug the Nix invocation in all the usual ways. +For example, enter `run` to start the Nix invocation. + +### Integration tests + +The integration tests are defined in the Nix flake under the `hydraJobs.tests` attribute. +These tests include everything that needs to interact with external services or run Nix in a non-trivial distributed setup. +Because these tests are expensive and require more than what the standard github-actions setup provides, they only run on the master branch (on <https://hydra.nixos.org/jobset/nix/master>). + +You can run them manually with `nix build .#hydraJobs.tests.{testName}` or `nix-build -A hydraJobs.tests.{testName}` + +### Installer tests + +After a one-time setup, the Nix repository's GitHub Actions continuous integration (CI) workflow can test the installer each time you push to a branch. + +Creating a Cachix cache for your installer tests and adding its authorization token to GitHub enables [two installer-specific jobs in the CI workflow](https://github.com/NixOS/nix/blob/88a45d6149c0e304f6eb2efcc2d7a4d0d569f8af/.github/workflows/ci.yml#L50-L91): + +- The `installer` job generates installers for the platforms below and uploads them to your Cachix cache: + - `x86_64-linux` + - `armv6l-linux` + - `armv7l-linux` + - `x86_64-darwin` + +- The `installer_test` job (which runs on `ubuntu-latest` and `macos-latest`) will try to install Nix with the cached installer and run a trivial Nix command. + +#### One-time setup + +1. Have a GitHub account with a fork of the [Nix repository](https://github.com/NixOS/nix). +2. At cachix.org: + - Create or log in to an account. + - Create a Cachix cache using the format `<github-username>-nix-install-tests`. + - Navigate to the new cache > Settings > Auth Tokens. + - Generate a new Cachix auth token and copy the generated value. +3. At github.com: + - Navigate to your Nix fork > Settings > Secrets > Actions > New repository secret. + - Name the secret `CACHIX_AUTH_TOKEN`. + - Paste the copied value of the Cachix cache auth token. + +#### Using the CI-generated installer for manual testing + +After the CI run completes, you can check the output to extract the installer URL: +1. Click into the detailed view of the CI run. +2. Click into any `installer_test` run (the URL you're here to extract will be the same in all of them). +3. Click into the `Run cachix/install-nix-action@v...` step and click the detail triangle next to the first log line (it will also be `Run cachix/install-nix-action@v...`) +4. Copy the value of `install_url` +5. To generate an install command, plug this `install_url` and your GitHub username into this template: + + ```console + sh <(curl -L <install_url>) --tarball-url-prefix https://<github-username>-nix-install-tests.cachix.org/serve + ``` + +<!-- #### Manually generating test installers + +There's obviously a manual way to do this, and it's still the only way for +platforms that lack GA runners. + +I did do this back in Fall 2020 (before the GA approach encouraged here). I'll +sketch what I recall in case it encourages someone to fill in detail, but: I +didn't know what I was doing at the time and had to fumble/ask around a lot-- +so I don't want to uphold any of it as "right". It may have been dumb or +the _hard_ way from the getgo. Fundamentals may have changed since. + +Here's the build command I used to do this on and for x86_64-darwin: +nix build --out-link /tmp/foo ".#checks.x86_64-darwin.binaryTarball" + +I used the stable out-link to make it easier to script the next steps: +link=$(readlink /tmp/foo) +cp $link/*-darwin.tar.xz ~/somewheres + +I've lost the last steps and am just going from memory: + +From here, I think I had to extract and modify the `install` script to point +it at this tarball (which I scped to my own site, but it might make more sense +to just share them locally). I extracted this script once and then just +search/replaced in it for each new build. + +The installer now supports a `--tarball-url-prefix` flag which _may_ have +solved this need? +--> diff --git a/doc/manual/src/expressions/arguments-variables.md b/doc/manual/src/expressions/arguments-variables.md deleted file mode 100644 index 12198c879..000000000 --- a/doc/manual/src/expressions/arguments-variables.md +++ /dev/null @@ -1,80 +0,0 @@ -# Arguments and Variables - -The [Nix expression for GNU Hello](expression-syntax.md) is a -function; it is missing some arguments that have to be filled in -somewhere. In the Nix Packages collection this is done in the file -`pkgs/top-level/all-packages.nix`, where all Nix expressions for -packages are imported and called with the appropriate arguments. Here -are some fragments of `all-packages.nix`, with annotations of what -they mean: - -```nix -... - -rec { ① - - hello = import ../applications/misc/hello/ex-1 ② { ③ - inherit fetchurl stdenv perl; - }; - - perl = import ../development/interpreters/perl { ④ - inherit fetchurl stdenv; - }; - - fetchurl = import ../build-support/fetchurl { - inherit stdenv; ... - }; - - stdenv = ...; - -} -``` - -1. This file defines a set of attributes, all of which are concrete - derivations (i.e., not functions). In fact, we define a *mutually - recursive* set of attributes. That is, the attributes can refer to - each other. This is precisely what we want since we want to “plug” - the various packages into each other. - -2. Here we *import* the Nix expression for GNU Hello. The import - operation just loads and returns the specified Nix expression. In - fact, we could just have put the contents of the Nix expression - for GNU Hello in `all-packages.nix` at this point. That would be - completely equivalent, but it would make `all-packages.nix` rather - bulky. - - Note that we refer to `../applications/misc/hello/ex-1`, not - `../applications/misc/hello/ex-1/default.nix`. When you try to - import a directory, Nix automatically appends `/default.nix` to the - file name. - -3. This is where the actual composition takes place. Here we *call* the - function imported from `../applications/misc/hello/ex-1` with a set - containing the things that the function expects, namely `fetchurl`, - `stdenv`, and `perl`. We use inherit again to use the attributes - defined in the surrounding scope (we could also have written - `fetchurl = fetchurl;`, etc.). - - The result of this function call is an actual derivation that can be - built by Nix (since when we fill in the arguments of the function, - what we get is its body, which is the call to `stdenv.mkDerivation` - in the [Nix expression for GNU Hello](expression-syntax.md)). - - > **Note** - > - > Nixpkgs has a convenience function `callPackage` that imports and - > calls a function, filling in any missing arguments by passing the - > corresponding attribute from the Nixpkgs set, like this: - > - > ```nix - > hello = callPackage ../applications/misc/hello/ex-1 { }; - > ``` - > - > If necessary, you can set or override arguments: - > - > ```nix - > hello = callPackage ../applications/misc/hello/ex-1 { stdenv = myStdenv; }; - > ``` - -4. Likewise, we have to instantiate Perl, `fetchurl`, and the standard - environment. diff --git a/doc/manual/src/expressions/build-script.md b/doc/manual/src/expressions/build-script.md deleted file mode 100644 index b1eacae88..000000000 --- a/doc/manual/src/expressions/build-script.md +++ /dev/null @@ -1,70 +0,0 @@ -# Build Script - -Here is the builder referenced from Hello's Nix expression (stored in -`pkgs/applications/misc/hello/ex-1/builder.sh`): - -```bash -source $stdenv/setup ① - -PATH=$perl/bin:$PATH ② - -tar xvfz $src ③ -cd hello-* -./configure --prefix=$out ④ -make ⑤ -make install -``` - -The builder can actually be made a lot shorter by using the *generic -builder* functions provided by `stdenv`, but here we write out the build -steps to elucidate what a builder does. It performs the following steps: - -1. When Nix runs a builder, it initially completely clears the - environment (except for the attributes declared in the derivation). - This is done to prevent undeclared inputs from being used in the - build process. If for example the `PATH` contained `/usr/bin`, then - you might accidentally use `/usr/bin/gcc`. - - So the first step is to set up the environment. This is done by - calling the `setup` script of the standard environment. The - environment variable `stdenv` points to the location of the - standard environment being used. (It wasn't specified explicitly - as an attribute in Hello's Nix expression, but `mkDerivation` adds - it automatically.) - -2. Since Hello needs Perl, we have to make sure that Perl is in the - `PATH`. The `perl` environment variable points to the location of - the Perl package (since it was passed in as an attribute to the - derivation), so `$perl/bin` is the directory containing the Perl - interpreter. - -3. Now we have to unpack the sources. The `src` attribute was bound to - the result of fetching the Hello source tarball from the network, so - the `src` environment variable points to the location in the Nix - store to which the tarball was downloaded. After unpacking, we `cd` - to the resulting source directory. - - The whole build is performed in a temporary directory created in - `/tmp`, by the way. This directory is removed after the builder - finishes, so there is no need to clean up the sources afterwards. - Also, the temporary directory is always newly created, so you don't - have to worry about files from previous builds interfering with the - current build. - -4. GNU Hello is a typical Autoconf-based package, so we first have to - run its `configure` script. In Nix every package is stored in a - separate location in the Nix store, for instance - `/nix/store/9a54ba97fb71b65fda531012d0443ce2-hello-2.1.1`. Nix - computes this path by cryptographically hashing all attributes of - the derivation. The path is passed to the builder through the `out` - environment variable. So here we give `configure` the parameter - `--prefix=$out` to cause Hello to be installed in the expected - location. - -5. Finally we build Hello (`make`) and install it into the location - specified by `out` (`make install`). - -If you are wondering about the absence of error checking on the result -of various commands called in the builder: this is because the shell -script is evaluated with Bash's `-e` option, which causes the script to -be aborted if any command fails without an error check. diff --git a/doc/manual/src/expressions/expression-language.md b/doc/manual/src/expressions/expression-language.md deleted file mode 100644 index 267fcb983..000000000 --- a/doc/manual/src/expressions/expression-language.md +++ /dev/null @@ -1,12 +0,0 @@ -# Nix Expression Language - -The Nix expression language is a pure, lazy, functional language. Purity -means that operations in the language don't have side-effects (for -instance, there is no variable assignment). Laziness means that -arguments to functions are evaluated only when they are needed. -Functional means that functions are “normal” values that can be passed -around and manipulated in interesting ways. The language is not a -full-featured, general purpose language. Its main job is to describe -packages, compositions of packages, and the variability within packages. - -This section presents the various features of the language. diff --git a/doc/manual/src/expressions/expression-syntax.md b/doc/manual/src/expressions/expression-syntax.md deleted file mode 100644 index 6b93e692c..000000000 --- a/doc/manual/src/expressions/expression-syntax.md +++ /dev/null @@ -1,93 +0,0 @@ -# Expression Syntax - -Here is a Nix expression for GNU Hello: - -```nix -{ stdenv, fetchurl, perl }: ① - -stdenv.mkDerivation { ② - name = "hello-2.1.1"; ③ - builder = ./builder.sh; ④ - src = fetchurl { ⑤ - url = "ftp://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz"; - sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465"; - }; - inherit perl; ⑥ -} -``` - -This file is actually already in the Nix Packages collection in -`pkgs/applications/misc/hello/ex-1/default.nix`. It is customary to -place each package in a separate directory and call the single Nix -expression in that directory `default.nix`. The file has the following -elements (referenced from the figure by number): - -1. This states that the expression is a *function* that expects to be - called with three arguments: `stdenv`, `fetchurl`, and `perl`. They - are needed to build Hello, but we don't know how to build them here; - that's why they are function arguments. `stdenv` is a package that - is used by almost all Nix Packages; it provides a - “standard” environment consisting of the things you would expect - in a basic Unix environment: a C/C++ compiler (GCC, to be precise), - the Bash shell, fundamental Unix tools such as `cp`, `grep`, `tar`, - etc. `fetchurl` is a function that downloads files. `perl` is the - Perl interpreter. - - Nix functions generally have the form `{ x, y, ..., z }: e` where - `x`, `y`, etc. are the names of the expected arguments, and where - *e* is the body of the function. So here, the entire remainder of - the file is the body of the function; when given the required - arguments, the body should describe how to build an instance of - the Hello package. - -2. So we have to build a package. Building something from other stuff - is called a *derivation* in Nix (as opposed to sources, which are - built by humans instead of computers). We perform a derivation by - calling `stdenv.mkDerivation`. `mkDerivation` is a function - provided by `stdenv` that builds a package from a set of - *attributes*. A set is just a list of key/value pairs where each - key is a string and each value is an arbitrary Nix - expression. They take the general form `{ name1 = expr1; ... - nameN = exprN; }`. - -3. The attribute `name` specifies the symbolic name and version of - the package. Nix doesn't really care about these things, but they - are used by for instance `nix-env -q` to show a “human-readable” - name for packages. This attribute is required by `mkDerivation`. - -4. The attribute `builder` specifies the builder. This attribute can - sometimes be omitted, in which case `mkDerivation` will fill in a - default builder (which does a `configure; make; make install`, in - essence). Hello is sufficiently simple that the default builder - would suffice, but in this case, we will show an actual builder - for educational purposes. The value `./builder.sh` refers to the - shell script shown in the [next section](build-script.md), - discussed below. - -5. The builder has to know what the sources of the package are. Here, - the attribute `src` is bound to the result of a call to the - `fetchurl` function. Given a URL and a SHA-256 hash of the expected - contents of the file at that URL, this function builds a derivation - that downloads the file and checks its hash. So the sources are a - dependency that like all other dependencies is built before Hello - itself is built. - - Instead of `src` any other name could have been used, and in fact - there can be any number of sources (bound to different attributes). - However, `src` is customary, and it's also expected by the default - builder (which we don't use in this example). - -6. Since the derivation requires Perl, we have to pass the value of the - `perl` function argument to the builder. All attributes in the set - are actually passed as environment variables to the builder, so - declaring an attribute - - ```nix - perl = perl; - ``` - - will do the trick: it binds an attribute `perl` to the function - argument which also happens to be called `perl`. However, it looks a - bit silly, so there is a shorter syntax. The `inherit` keyword - causes the specified attributes to be bound to whatever variables - with the same name happen to be in scope. diff --git a/doc/manual/src/expressions/generic-builder.md b/doc/manual/src/expressions/generic-builder.md deleted file mode 100644 index cf26b5f82..000000000 --- a/doc/manual/src/expressions/generic-builder.md +++ /dev/null @@ -1,66 +0,0 @@ -# Generic Builder Syntax - -Recall that the [build script for GNU Hello](build-script.md) looked -something like this: - -```bash -PATH=$perl/bin:$PATH -tar xvfz $src -cd hello-* -./configure --prefix=$out -make -make install -``` - -The builders for almost all Unix packages look like this — set up some -environment variables, unpack the sources, configure, build, and -install. For this reason the standard environment provides some Bash -functions that automate the build process. Here is what a builder using -the generic build facilities looks like: - -```bash -buildInputs="$perl" ① - -source $stdenv/setup ② - -genericBuild ③ -``` - -Here is what each line means: - -1. The `buildInputs` variable tells `setup` to use the indicated - packages as “inputs”. This means that if a package provides a `bin` - subdirectory, it's added to `PATH`; if it has a `include` - subdirectory, it's added to GCC's header search path; and so on. - (This is implemented in a modular way: `setup` tries to source the - file `pkg/nix-support/setup-hook` of all dependencies. These “setup - hooks” can then set up whatever environment variables they want; for - instance, the setup hook for Perl sets the `PERL5LIB` environment - variable to contain the `lib/site_perl` directories of all inputs.) - -2. The function `genericBuild` is defined in the file `$stdenv/setup`. - -3. The final step calls the shell function `genericBuild`, which - performs the steps that were done explicitly in the previous build - script. The generic builder is smart enough to figure out whether - to unpack the sources using `gzip`, `bzip2`, etc. It can be - customised in many ways; see the Nixpkgs manual for details. - -Discerning readers will note that the `buildInputs` could just as well -have been set in the Nix expression, like this: - -```nix - buildInputs = [ perl ]; -``` - -The `perl` attribute can then be removed, and the builder becomes even -shorter: - -```bash -source $stdenv/setup -genericBuild -``` - -In fact, `mkDerivation` provides a default builder that looks exactly -like that, so it is actually possible to omit the builder for Hello -entirely. diff --git a/doc/manual/src/expressions/language-operators.md b/doc/manual/src/expressions/language-operators.md deleted file mode 100644 index 268b44f4c..000000000 --- a/doc/manual/src/expressions/language-operators.md +++ /dev/null @@ -1,28 +0,0 @@ -# Operators - -The table below lists the operators in the Nix expression language, in -order of precedence (from strongest to weakest binding). - -| Name | Syntax | Associativity | Description | Precedence | -| ------------------------ | ----------------------------------- | ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- | -| Select | *e* `.` *attrpath* \[ `or` *def* \] | none | Select attribute denoted by the attribute path *attrpath* from set *e*. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist, return *def* if provided, otherwise abort evaluation. | 1 | -| Application | *e1* *e2* | left | Call function *e1* with argument *e2*. | 2 | -| Arithmetic Negation | `-` *e* | none | Arithmetic negation. | 3 | -| Has Attribute | *e* `?` *attrpath* | none | Test whether set *e* contains the attribute denoted by *attrpath*; return `true` or `false`. | 4 | -| List Concatenation | *e1* `++` *e2* | right | List concatenation. | 5 | -| Multiplication | *e1* `*` *e2*, | left | Arithmetic multiplication. | 6 | -| Division | *e1* `/` *e2* | left | Arithmetic division. | 6 | -| Addition | *e1* `+` *e2* | left | Arithmetic addition. | 7 | -| Subtraction | *e1* `-` *e2* | left | Arithmetic subtraction. | 7 | -| String Concatenation | *string1* `+` *string2* | left | String concatenation. | 7 | -| Not | `!` *e* | none | Boolean negation. | 8 | -| Update | *e1* `//` *e2* | right | Return a set consisting of the attributes in *e1* and *e2* (with the latter taking precedence over the former in case of equally named attributes). | 9 | -| Less Than | *e1* `<` *e2*, | none | Arithmetic/lexicographic comparison. | 10 | -| Less Than or Equal To | *e1* `<=` *e2* | none | Arithmetic/lexicographic comparison. | 10 | -| Greater Than | *e1* `>` *e2* | none | Arithmetic/lexicographic comparison. | 10 | -| Greater Than or Equal To | *e1* `>=` *e2* | none | Arithmetic/lexicographic comparison. | 10 | -| Equality | *e1* `==` *e2* | none | Equality. | 11 | -| Inequality | *e1* `!=` *e2* | none | Inequality. | 11 | -| Logical AND | *e1* `&&` *e2* | left | Logical AND. | 12 | -| Logical OR | *e1* <code>||</code> *e2* | left | Logical OR. | 13 | -| Logical Implication | *e1* `->` *e2* | none | Logical implication (equivalent to <code>!e1 || e2</code>). | 14 | diff --git a/doc/manual/src/expressions/language-values.md b/doc/manual/src/expressions/language-values.md deleted file mode 100644 index 75ae9f2eb..000000000 --- a/doc/manual/src/expressions/language-values.md +++ /dev/null @@ -1,251 +0,0 @@ -# Values - -## Simple Values - -Nix has the following basic data types: - - - *Strings* can be written in three ways. - - The most common way is to enclose the string between double quotes, - e.g., `"foo bar"`. Strings can span multiple lines. The special - characters `"` and `\` and the character sequence `${` must be - escaped by prefixing them with a backslash (`\`). Newlines, carriage - returns and tabs can be written as `\n`, `\r` and `\t`, - respectively. - - You can include the result of an expression into a string by - enclosing it in `${...}`, a feature known as *antiquotation*. The - enclosed expression must evaluate to something that can be coerced - into a string (meaning that it must be a string, a path, or a - derivation). For instance, rather than writing - - ```nix - "--with-freetype2-library=" + freetype + "/lib" - ``` - - (where `freetype` is a derivation), you can instead write the more - natural - - ```nix - "--with-freetype2-library=${freetype}/lib" - ``` - - The latter is automatically translated to the former. A more - complicated example (from the Nix expression for - [Qt](http://www.trolltech.com/products/qt)): - - ```nix - configureFlags = " - -system-zlib -system-libpng -system-libjpeg - ${if openglSupport then "-dlopen-opengl - -L${mesa}/lib -I${mesa}/include - -L${libXmu}/lib -I${libXmu}/include" else ""} - ${if threadSupport then "-thread" else "-no-thread"} - "; - ``` - - Note that Nix expressions and strings can be arbitrarily nested; in - this case the outer string contains various antiquotations that - themselves contain strings (e.g., `"-thread"`), some of which in - turn contain expressions (e.g., `${mesa}`). - - The second way to write string literals is as an *indented string*, - which is enclosed between pairs of *double single-quotes*, like so: - - ```nix - '' - This is the first line. - This is the second line. - This is the third line. - '' - ``` - - This kind of string literal intelligently strips indentation from - the start of each line. To be precise, it strips from each line a - number of spaces equal to the minimal indentation of the string as a - whole (disregarding the indentation of empty lines). For instance, - the first and second line are indented two spaces, while the third - line is indented four spaces. Thus, two spaces are stripped from - each line, so the resulting string is - - ```nix - "This is the first line.\nThis is the second line.\n This is the third line.\n" - ``` - - Note that the whitespace and newline following the opening `''` is - ignored if there is no non-whitespace text on the initial line. - - Antiquotation (`${expr}`) is supported in indented strings. - - Since `${` and `''` have special meaning in indented strings, you - need a way to quote them. `$` can be escaped by prefixing it with - `''` (that is, two single quotes), i.e., `''$`. `''` can be escaped - by prefixing it with `'`, i.e., `'''`. `$` removes any special - meaning from the following `$`. Linefeed, carriage-return and tab - characters can be written as `''\n`, `''\r`, `''\t`, and `''\` - escapes any other character. - - Indented strings are primarily useful in that they allow multi-line - string literals to follow the indentation of the enclosing Nix - expression, and that less escaping is typically necessary for - strings representing languages such as shell scripts and - configuration files because `''` is much less common than `"`. - Example: - - ```nix - stdenv.mkDerivation { - ... - postInstall = - '' - mkdir $out/bin $out/etc - cp foo $out/bin - echo "Hello World" > $out/etc/foo.conf - ${if enableBar then "cp bar $out/bin" else ""} - ''; - ... - } - ``` - - Finally, as a convenience, *URIs* as defined in appendix B of - [RFC 2396](http://www.ietf.org/rfc/rfc2396.txt) can be written *as - is*, without quotes. For instance, the string - `"http://example.org/foo.tar.bz2"` can also be written as - `http://example.org/foo.tar.bz2`. - - - Numbers, which can be *integers* (like `123`) or *floating point* - (like `123.43` or `.27e13`). - - Numbers are type-compatible: pure integer operations will always - return integers, whereas any operation involving at least one - floating point number will have a floating point number as a result. - - - *Paths*, e.g., `/bin/sh` or `./builder.sh`. A path must contain at - least one slash to be recognised as such. For instance, `builder.sh` - is not a path: it's parsed as an expression that selects the - attribute `sh` from the variable `builder`. If the file name is - relative, i.e., if it does not begin with a slash, it is made - absolute at parse time relative to the directory of the Nix - expression that contained it. For instance, if a Nix expression in - `/foo/bar/bla.nix` refers to `../xyzzy/fnord.nix`, the absolute path - is `/foo/xyzzy/fnord.nix`. - - If the first component of a path is a `~`, it is interpreted as if - the rest of the path were relative to the user's home directory. - e.g. `~/foo` would be equivalent to `/home/edolstra/foo` for a user - whose home directory is `/home/edolstra`. - - Paths can also be specified between angle brackets, e.g. - `<nixpkgs>`. This means that the directories listed in the - environment variable `NIX_PATH` will be searched for the given file - or directory name. - - Antiquotation is supported in any paths except those in angle brackets. - `./${foo}-${bar}.nix` is a more convenient way of writing - `./. + "/" + foo + "-" + bar + ".nix"` or `./. + "/${foo}-${bar}.nix"`. At - least one slash must appear *before* any antiquotations for this to be - recognized as a path. `a.${foo}/b.${bar}` is a syntactically valid division - operation. `./a.${foo}/b.${bar}` is a path. - - - *Booleans* with values `true` and `false`. - - - The null value, denoted as `null`. - -## Lists - -Lists are formed by enclosing a whitespace-separated list of values -between square brackets. For example, - -```nix -[ 123 ./foo.nix "abc" (f { x = y; }) ] -``` - -defines a list of four elements, the last being the result of a call to -the function `f`. Note that function calls have to be enclosed in -parentheses. If they had been omitted, e.g., - -```nix -[ 123 ./foo.nix "abc" f { x = y; } ] -``` - -the result would be a list of five elements, the fourth one being a -function and the fifth being a set. - -Note that lists are only lazy in values, and they are strict in length. - -## Sets - -Sets are really the core of the language, since ultimately the Nix -language is all about creating derivations, which are really just sets -of attributes to be passed to build scripts. - -Sets are just a list of name/value pairs (called *attributes*) enclosed -in curly brackets, where each value is an arbitrary expression -terminated by a semicolon. For example: - -```nix -{ x = 123; - text = "Hello"; - y = f { bla = 456; }; -} -``` - -This defines a set with attributes named `x`, `text`, `y`. The order of -the attributes is irrelevant. An attribute name may only occur once. - -Attributes can be selected from a set using the `.` operator. For -instance, - -```nix -{ a = "Foo"; b = "Bar"; }.a -``` - -evaluates to `"Foo"`. It is possible to provide a default value in an -attribute selection using the `or` keyword. For example, - -```nix -{ a = "Foo"; b = "Bar"; }.c or "Xyzzy" -``` - -will evaluate to `"Xyzzy"` because there is no `c` attribute in the set. - -You can use arbitrary double-quoted strings as attribute names: - -```nix -{ "foo ${bar}" = 123; "nix-1.0" = 456; }."foo ${bar}" -``` - -This will evaluate to `123` (Assuming `bar` is antiquotable). In the -case where an attribute name is just a single antiquotation, the quotes -can be dropped: - -```nix -{ foo = 123; }.${bar} or 456 -``` - -This will evaluate to `123` if `bar` evaluates to `"foo"` when coerced -to a string and `456` otherwise (again assuming `bar` is antiquotable). - -In the special case where an attribute name inside of a set declaration -evaluates to `null` (which is normally an error, as `null` is not -antiquotable), that attribute is simply not added to the set: - -```nix -{ ${if foo then "bar" else null} = true; } -``` - -This will evaluate to `{}` if `foo` evaluates to `false`. - -A set that has a `__functor` attribute whose value is callable (i.e. is -itself a function or a set with a `__functor` attribute whose value is -callable) can be applied as if it were a function, with the set itself -passed in first , e.g., - -```nix -let add = { __functor = self: x: x + self.x; }; - inc = add // { x = 1; }; -in inc 1 -``` - -evaluates to `2`. This can be used to attach metadata to a function -without the caller needing to treat it specially, or to implement a form -of object-oriented programming, for example. diff --git a/doc/manual/src/expressions/simple-building-testing.md b/doc/manual/src/expressions/simple-building-testing.md deleted file mode 100644 index 7f0d8f841..000000000 --- a/doc/manual/src/expressions/simple-building-testing.md +++ /dev/null @@ -1,61 +0,0 @@ -# Building and Testing - -You can now try to build Hello. Of course, you could do `nix-env -f . -iA -hello`, but you may not want to install a possibly broken package just -yet. The best way to test the package is by using the command -`nix-build`, which builds a Nix expression and creates a symlink named -`result` in the current directory: - -```console -$ nix-build -A hello -building path `/nix/store/632d2b22514d...-hello-2.1.1' -hello-2.1.1/ -hello-2.1.1/intl/ -hello-2.1.1/intl/ChangeLog -... - -$ ls -l result -lrwxrwxrwx ... 2006-09-29 10:43 result -> /nix/store/632d2b22514d...-hello-2.1.1 - -$ ./result/bin/hello -Hello, world! -``` - -The `-A` option selects the `hello` attribute. This is faster than -using the symbolic package name specified by the `name` attribute -(which also happens to be `hello`) and is unambiguous (there can be -multiple packages with the symbolic name `hello`, but there can be -only one attribute in a set named `hello`). - -`nix-build` registers the `./result` symlink as a garbage collection -root, so unless and until you delete the `./result` symlink, the output -of the build will be safely kept on your system. You can use -`nix-build`’s `-o` switch to give the symlink another name. - -Nix has transactional semantics. Once a build finishes successfully, Nix -makes a note of this in its database: it registers that the path denoted -by `out` is now “valid”. If you try to build the derivation again, Nix -will see that the path is already valid and finish immediately. If a -build fails, either because it returns a non-zero exit code, because Nix -or the builder are killed, or because the machine crashes, then the -output paths will not be registered as valid. If you try to build the -derivation again, Nix will remove the output paths if they exist (e.g., -because the builder died half-way through `make -install`) and try again. Note that there is no “negative caching”: Nix -doesn't remember that a build failed, and so a failed build can always -be repeated. This is because Nix cannot distinguish between permanent -failures (e.g., a compiler error due to a syntax error in the source) -and transient failures (e.g., a disk full condition). - -Nix also performs locking. If you run multiple Nix builds -simultaneously, and they try to build the same derivation, the first Nix -instance that gets there will perform the build, while the others block -(or perform other derivations if available) until the build finishes: - -```console -$ nix-build -A hello -waiting for lock on `/nix/store/0h5b7hp8d4hqfrw8igvx97x1xawrjnac-hello-2.1.1x' -``` - -So it is always safe to run multiple instances of Nix in parallel (which -isn’t the case with, say, `make`). diff --git a/doc/manual/src/expressions/simple-expression.md b/doc/manual/src/expressions/simple-expression.md deleted file mode 100644 index 857f71b9b..000000000 --- a/doc/manual/src/expressions/simple-expression.md +++ /dev/null @@ -1,23 +0,0 @@ -# A Simple Nix Expression - -This section shows how to add and test the [GNU Hello -package](http://www.gnu.org/software/hello/hello.html) to the Nix -Packages collection. Hello is a program that prints out the text “Hello, -world\!”. - -To add a package to the Nix Packages collection, you generally need to -do three things: - -1. Write a Nix expression for the package. This is a file that - describes all the inputs involved in building the package, such as - dependencies, sources, and so on. - -2. Write a *builder*. This is a shell script that builds the package - from the inputs. (In fact, it can be written in any language, but - typically it's a `bash` shell script.) - -3. Add the package to the file `pkgs/top-level/all-packages.nix`. The - Nix expression written in the first step is a *function*; it - requires other packages in order to build it. In this step you put - it all together, i.e., you call the function with the right - arguments to build the actual package. diff --git a/doc/manual/src/expressions/writing-nix-expressions.md b/doc/manual/src/expressions/writing-nix-expressions.md deleted file mode 100644 index 5664108e7..000000000 --- a/doc/manual/src/expressions/writing-nix-expressions.md +++ /dev/null @@ -1,12 +0,0 @@ -This chapter shows you how to write Nix expressions, which instruct Nix -how to build packages. It starts with a simple example (a Nix expression -for GNU Hello), and then moves on to a more in-depth look at the Nix -expression language. - -> **Note** -> -> This chapter is mostly about the Nix expression language. For more -> extensive information on adding packages to the Nix Packages -> collection (such as functions in the standard environment and coding -> conventions), please consult [its -> manual](http://nixos.org/nixpkgs/manual/). diff --git a/doc/manual/src/glossary.md b/doc/manual/src/glossary.md index 71ff13275..e63f6becc 100644 --- a/doc/manual/src/glossary.md +++ b/doc/manual/src/glossary.md @@ -1,48 +1,120 @@ # Glossary - - derivation\ - A description of a build action. The result of a derivation is a + - [derivation]{#gloss-derivation}\ + A description of a build task. The result of a derivation is a store object. Derivations are typically specified in Nix expressions - using the [`derivation` primitive](expressions/derivations.md). These are + using the [`derivation` primitive](./language/derivations.md). These are translated into low-level *store derivations* (implicitly by `nix-env` and `nix-build`, or explicitly by `nix-instantiate`). - - store\ + [derivation]: #gloss-derivation + + - [store derivation]{#gloss-store-derivation}\ + A [derivation] represented as a `.drv` file in the [store]. + It has a [store path], like any [store object]. + + Example: `/nix/store/g946hcz4c8mdvq2g8vxx42z51qb71rvp-git-2.38.1.drv` + + See [`nix show-derivation`](./command-ref/new-cli/nix3-show-derivation.md) (experimental) for displaying the contents of store derivations. + + [store derivation]: #gloss-store-derivation + + - [content-addressed derivation]{#gloss-content-addressed-derivation}\ + A derivation which has the + [`__contentAddressed`](./language/advanced-attributes.md#adv-attr-__contentAddressed) + attribute set to `true`. + + - [fixed-output derivation]{#gloss-fixed-output-derivation}\ + A derivation which includes the + [`outputHash`](./language/advanced-attributes.md#adv-attr-outputHash) attribute. + + - [store]{#gloss-store}\ The location in the file system where store objects live. Typically `/nix/store`. - - store path\ - The location in the file system of a store object, i.e., an + From the perspective of the location where Nix is + invoked, the Nix store can be referred to + as a "_local_" or a "_remote_" one: + + + A *local store* exists on the filesystem of + the machine where Nix is invoked. You can use other + local stores by passing the `--store` flag to the + `nix` command. Local stores can be used for building derivations. + + + A *remote store* exists anywhere other than the + local filesystem. One example is the `/nix/store` + directory on another machine, accessed via `ssh` or + served by the `nix-serve` Perl script. + + [store]: #gloss-store + + - [chroot store]{#gloss-chroot-store}\ + A local store whose canonical path is anything other than `/nix/store`. + + - [binary cache]{#gloss-binary-cache}\ + A *binary cache* is a Nix store which uses a different format: its + metadata and signatures are kept in `.narinfo` files rather than in a + Nix database. This different format simplifies serving store objects + over the network, but cannot host builds. Examples of binary caches + include S3 buckets and the [NixOS binary + cache](https://cache.nixos.org). + + - [store path]{#gloss-store-path}\ + The location of a [store object] in the file system, i.e., an immediate child of the Nix store directory. - - store object\ + Example: `/nix/store/a040m110amc4h71lds2jmr8qrkj2jhxd-git-2.38.1` + + [store path]: #gloss-store-path + + - [store object]{#gloss-store-object}\ A file that is an immediate child of the Nix store directory. These can be regular files, but also entire directory trees. Store objects can be sources (objects copied from outside of the store), - derivation outputs (objects produced by running a build action), or - derivations (files describing a build action). + derivation outputs (objects produced by running a build task), or + derivations (files describing a build task). + + [store object]: #gloss-store-object - - substitute\ + - [input-addressed store object]{#gloss-input-addressed-store-object}\ + A store object produced by building a + non-[content-addressed](#gloss-content-addressed-derivation), + non-[fixed-output](#gloss-fixed-output-derivation) + derivation. + + - [output-addressed store object]{#gloss-output-addressed-store-object}\ + A store object whose store path hashes its content. This + includes derivations, the outputs of + [content-addressed derivations](#gloss-content-addressed-derivation), + and the outputs of + [fixed-output derivations](#gloss-fixed-output-derivation). + + - [substitute]{#gloss-substitute}\ A substitute is a command invocation stored in the Nix database that describes how to build a store object, bypassing the normal build mechanism (i.e., derivations). Typically, the substitute builds the store object by downloading a pre-built version of the store object from some server. - - purity\ + - [substituter]{#gloss-substituter}\ + A *substituter* is an additional store from which Nix will + copy store objects it doesn't have. For details, see the + [`substituters` option](./command-ref/conf-file.md#conf-substituters). + + - [purity]{#gloss-purity}\ The assumption that equal Nix derivations when run always produce the same output. This cannot be guaranteed in general (e.g., a builder can rely on external inputs such as the network or the system time) but the Nix model assumes it. - - Nix expression\ + - [Nix expression]{#gloss-nix-expression}\ A high-level description of software packages and compositions thereof. Deploying software using Nix entails writing Nix expressions for your packages. Nix expressions are translated to derivations that are stored in the Nix store. These derivations can then be built. - - reference\ + - [reference]{#gloss-reference}\ A store path `P` is said to have a reference to a store path `Q` if the store object at `P` contains the path `Q` somewhere. The *references* of a store path are the set of store paths to which it @@ -52,11 +124,11 @@ output paths), whereas an output path only references other output paths. - - reachable\ + - [reachable]{#gloss-reachable}\ A store path `Q` is reachable from another store path `P` if `Q` is in the *closure* of the *references* relation. - - closure\ + - [closure]{#gloss-closure}\ The closure of a store path is the set of store paths that are directly or indirectly “reachable” from that store path; that is, it’s the closure of the path under the *references* relation. For @@ -71,34 +143,47 @@ to path `Q`, then `Q` is in the closure of `P`. Further, if `Q` references `R` then `R` is also in the closure of `P`. - - output path\ - A store path produced by a derivation. + - [output path]{#gloss-output-path}\ + A [store path] produced by a [derivation]. - - deriver\ + [output path]: #gloss-output-path + + - [deriver]{#gloss-deriver}\ The deriver of an *output path* is the store derivation that built it. - - validity\ + - [validity]{#gloss-validity}\ A store path is considered *valid* if it exists in the file system, is listed in the Nix database as being valid, and if all paths in its closure are also valid. - - user environment\ + - [user environment]{#gloss-user-env}\ An automatically generated store object that consists of a set of symlinks to “active” applications, i.e., other store paths. These are generated automatically by - [`nix-env`](command-ref/nix-env.md). See *profiles*. + [`nix-env`](./command-ref/nix-env.md). See *profiles*. - - profile\ + - [profile]{#gloss-profile}\ A symlink to the current *user environment* of a user, e.g., `/nix/var/nix/profiles/default`. - - NAR\ + - [NAR]{#gloss-nar}\ A *N*ix *AR*chive. This is a serialisation of a path in the Nix store. It can contain regular files, directories and symbolic links. NARs are generated and unpacked using `nix-store --dump` and `nix-store --restore`. - - `∅` \ + + - [`∅`]{#gloss-emtpy-set}\ The empty set symbol. In the context of profile history, this denotes a package is not present in a particular version of the profile. - - `ε` \ + + - [`ε`]{#gloss-epsilon}\ The epsilon symbol. In the context of a package, this means the version is empty. More precisely, the derivation does not have a version attribute. + + - [string interpolation]{#gloss-string-interpolation}\ + Expanding expressions enclosed in `${ }` within a [string], [path], or [attribute name]. + + See [String interpolation](./language/string-interpolation.md) for details. + + [string]: ./language/values.md#type-string + [path]: ./language/values.md#type-path + [attribute name]: ./language/values.md#attribute-set diff --git a/doc/manual/src/installation/installing-binary.md b/doc/manual/src/installation/installing-binary.md index e5fb50088..53fdbe31a 100644 --- a/doc/manual/src/installation/installing-binary.md +++ b/doc/manual/src/installation/installing-binary.md @@ -13,7 +13,7 @@ for your platform: - multi-user on macOS > **Notes on read-only filesystem root in macOS 10.15 Catalina +** - > + > > - It took some time to support this cleanly. You may see posts, > examples, and tutorials using obsolete workarounds. > - Supporting it cleanly made macOS installs too complex to qualify @@ -31,8 +31,8 @@ $ sh <(curl -L https://nixos.org/nix/install) --no-daemon ``` This will perform a single-user installation of Nix, meaning that `/nix` -is owned by the invoking user. You should run this under your usual user -account, *not* as root. The script will invoke `sudo` to create `/nix` +is owned by the invoking user. You can run this under your usual user +account or root. The script will invoke `sudo` to create `/nix` if it doesn’t already exist. If you don’t have `sudo`, you should manually create `/nix` first as root, e.g.: @@ -71,11 +71,11 @@ $ sh <(curl -L https://nixos.org/nix/install) --daemon The multi-user installation of Nix will create build users between the user IDs 30001 and 30032, and a group with the group ID 30000. You -should run this under your usual user account, *not* as root. The script +can run this under your usual user account or root. The script will invoke `sudo` as needed. > **Note** -> +> > If you need Nix to use a different group ID or user ID set, you will > have to download the tarball manually and [edit the install > script](#installing-from-a-binary-tarball). @@ -88,19 +88,51 @@ extension. The installer will also create `/etc/profile.d/nix.sh`. ### Linux +If you are on Linux with systemd: + +1. Remove the Nix daemon service: + + ```console + sudo systemctl stop nix-daemon.service + sudo systemctl disable nix-daemon.socket nix-daemon.service + sudo systemctl daemon-reload + ``` + +1. Remove systemd service files: + + ```console + sudo rm /etc/systemd/system/nix-daemon.service /etc/systemd/system/nix-daemon.socket + ``` + +1. The installer script uses systemd-tmpfiles to create the socket directory. + You may also want to remove the configuration for that: + + ```console + sudo rm /etc/tmpfiles.d/nix-daemon.conf + ``` + +Remove files created by Nix: + ```console -sudo rm -rf /etc/profile/nix.sh /etc/nix /nix ~root/.nix-profile ~root/.nix-defexpr ~root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels - -# If you are on Linux with systemd, you will need to run: -sudo systemctl stop nix-daemon.socket -sudo systemctl stop nix-daemon.service -sudo systemctl disable nix-daemon.socket -sudo systemctl disable nix-daemon.service -sudo systemctl daemon-reload +sudo rm -rf /nix /etc/nix /etc/profile/nix.sh ~root/.nix-profile ~root/.nix-defexpr ~root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels ``` -There may also be references to Nix in `/etc/profile`, `/etc/bashrc`, -and `/etc/zshrc` which you may remove. +Remove build users and their group: + +```console +for i in $(seq 1 32); do + sudo userdel nixbld$i +done +sudo groupdel nixbld +``` + +There may also be references to Nix in + +- `/etc/profile` +- `/etc/bashrc` +- `/etc/zshrc` + +which you may remove. ### macOS @@ -148,7 +180,8 @@ and `/etc/zshrc` which you may remove. This will remove all the build users that no longer serve a purpose. 4. Edit fstab using `sudo vifs` to remove the line mounting the Nix Store - volume on `/nix`, which looks like this, + volume on `/nix`, which looks like + `UUID=<uuid> /nix apfs rw,noauto,nobrowse,suid,owners` or `LABEL=Nix\040Store /nix apfs rw,nobrowse`. This will prevent automatic mounting of the Nix Store volume. @@ -167,7 +200,7 @@ and `/etc/zshrc` which you may remove. removed next. 7. Remove the Nix Store volume: - + ```console sudo diskutil apfs deleteVolume /nix ``` @@ -175,8 +208,20 @@ and `/etc/zshrc` which you may remove. This will remove the Nix Store volume and everything that was added to the store. + If the output indicates that the command couldn't remove the volume, you should + make sure you don't have an _unmounted_ Nix Store volume. Look for a + "Nix Store" volume in the output of the following command: + + ```console + diskutil list + ``` + + If you _do_ see a "Nix Store" volume, delete it by re-running the diskutil + deleteVolume command, but replace `/nix` with the store volume's `diskXsY` + identifier. + > **Note** -> +> > After you complete the steps here, you will still have an empty `/nix` > directory. This is an expected sign of a successful uninstall. The empty > `/nix` directory will disappear the next time you reboot. @@ -186,12 +231,12 @@ and `/etc/zshrc` which you may remove. > read-only root will prevent you from manually deleting the empty `/nix` > mountpoint. -# macOS Installation <a name="sect-macos-installation-change-store-prefix"></a><a name="sect-macos-installation-encrypted-volume"></a><a name="sect-macos-installation-symlink"></a><a name="sect-macos-installation-recommended-notes"></a> +# macOS Installation +[]{#sect-macos-installation-change-store-prefix}[]{#sect-macos-installation-encrypted-volume}[]{#sect-macos-installation-symlink}[]{#sect-macos-installation-recommended-notes} <!-- Note: anchors above to catch permalinks to old explanations --> We believe we have ironed out how to cleanly support the read-only root -on modern macOS. New installs will do this automatically, and you can -also re-run a new installer to convert your existing setup. +on modern macOS. New installs will do this automatically. This section previously detailed the situation, options, and trade-offs, but it now only outlines what the installer does. You don't need to know diff --git a/doc/manual/src/introduction.md b/doc/manual/src/introduction.md index d87487a07..b54346db8 100644 --- a/doc/manual/src/introduction.md +++ b/doc/manual/src/introduction.md @@ -104,7 +104,7 @@ a currently running program. Packages are built from _Nix expressions_, which is a simple functional language. A Nix expression describes everything that goes -into a package build action (a “derivation”): other packages, sources, +into a package build task (a “derivation”): other packages, sources, the build script, environment variables for the build script, etc. Nix tries very hard to ensure that Nix expressions are _deterministic_: building a Nix expression twice should yield the same diff --git a/doc/manual/src/expressions/advanced-attributes.md b/doc/manual/src/language/advanced-attributes.md index 000595815..2e7e80ed0 100644 --- a/doc/manual/src/expressions/advanced-attributes.md +++ b/doc/manual/src/language/advanced-attributes.md @@ -2,7 +2,7 @@ Derivations can declare some infrequently used optional attributes. - - `allowedReferences`\ + - [`allowedReferences`]{#adv-attr-allowedReferences}\ The optional attribute `allowedReferences` specifies a list of legal references (dependencies) of the output of the builder. For example, @@ -17,7 +17,7 @@ Derivations can declare some infrequently used optional attributes. booting Linux don’t have accidental dependencies on other paths in the Nix store. - - `allowedRequisites`\ + - [`allowedRequisites`]{#adv-attr-allowedRequisites}\ This attribute is similar to `allowedReferences`, but it specifies the legal requisites of the whole closure, so all the dependencies recursively. For example, @@ -30,7 +30,7 @@ Derivations can declare some infrequently used optional attributes. runtime dependency than `foobar`, and in addition it enforces that `foobar` itself doesn't introduce any other dependency itself. - - `disallowedReferences`\ + - [`disallowedReferences`]{#adv-attr-disallowedReferences}\ The optional attribute `disallowedReferences` specifies a list of illegal references (dependencies) of the output of the builder. For example, @@ -42,7 +42,7 @@ Derivations can declare some infrequently used optional attributes. enforces that the output of a derivation cannot have a direct runtime dependencies on the derivation `foo`. - - `disallowedRequisites`\ + - [`disallowedRequisites`]{#adv-attr-disallowedRequisites}\ This attribute is similar to `disallowedReferences`, but it specifies illegal requisites for the whole closure, so all the dependencies recursively. For example, @@ -55,7 +55,7 @@ Derivations can declare some infrequently used optional attributes. dependency on `foobar` or any other derivation depending recursively on `foobar`. - - `exportReferencesGraph`\ + - [`exportReferencesGraph`]{#adv-attr-exportReferencesGraph}\ This attribute allows builders access to the references graph of their inputs. The attribute is a list of inputs in the Nix store whose references graph the builder needs to know. The value of @@ -84,7 +84,7 @@ Derivations can declare some infrequently used optional attributes. with a Nix store containing the closure of a bootable NixOS configuration). - - `impureEnvVars`\ + - [`impureEnvVars`]{#adv-attr-impureEnvVars}\ This attribute allows you to specify a list of environment variables that should be passed from the environment of the calling user to the builder. Usually, the environment is cleared completely when the @@ -112,7 +112,7 @@ Derivations can declare some infrequently used optional attributes. > environmental variables come from the environment of the > `nix-build`. - - `outputHash`; `outputHashAlgo`; `outputHashMode`\ + - [`outputHash`]{#adv-attr-outputHash}; [`outputHashAlgo`]{#adv-attr-outputHashAlgo}; [`outputHashMode`]{#adv-attr-outputHashMode}\ These attributes declare that the derivation is a so-called *fixed-output derivation*, which means that a cryptographic hash of the output is already known in advance. When the build of a @@ -208,7 +208,7 @@ Derivations can declare some infrequently used optional attributes. [`nix-hash` command](../command-ref/nix-hash.md) for information about converting to and from base-32 notation.) - - `__contentAddressed` + - [`__contentAddressed`]{#adv-attr-__contentAddressed} If this **experimental** attribute is set to true, then the derivation outputs will be stored in a content-addressed location rather than the traditional input-addressed one. @@ -216,7 +216,7 @@ Derivations can declare some infrequently used optional attributes. Setting this attribute also requires setting `outputHashMode` and `outputHashAlgo` like for *fixed-output derivations* (see above). - - `passAsFile`\ + - [`passAsFile`]{#adv-attr-passAsFile}\ A list of names of attributes that should be passed via files rather than environment variables. For example, if you have @@ -234,7 +234,7 @@ Derivations can declare some infrequently used optional attributes. builder, since most operating systems impose a limit on the size of the environment (typically, a few hundred kilobyte). - - `preferLocalBuild`\ + - [`preferLocalBuild`]{#adv-attr-preferLocalBuild}\ If this attribute is set to `true` and [distributed building is enabled](../advanced-topics/distributed-builds.md), then, if possible, the derivation will be built locally instead of forwarded @@ -242,7 +242,7 @@ Derivations can declare some infrequently used optional attributes. where the cost of doing a download or remote build would exceed the cost of building locally. - - `allowSubstitutes`\ + - [`allowSubstitutes`]{#adv-attr-allowSubstitutes}\ If this attribute is set to `false`, then Nix will always build this derivation; it will not try to substitute its outputs. This is useful for very trivial derivations (such as `writeText` in Nixpkgs) diff --git a/doc/manual/src/expressions/builtin-constants.md b/doc/manual/src/language/builtin-constants.md index 1404289e5..78d066a82 100644 --- a/doc/manual/src/expressions/builtin-constants.md +++ b/doc/manual/src/language/builtin-constants.md @@ -14,7 +14,7 @@ Here are the constants built into the Nix expression evaluator: This allows a Nix expression to fall back gracefully on older Nix installations that don’t have the desired built-in function. - - `builtins.currentSystem`\ + - [`builtins.currentSystem`]{#builtins-currentSystem}\ The built-in value `currentSystem` evaluates to the Nix platform identifier for the Nix installation on which the expression is being evaluated, such as `"i686-linux"` or `"x86_64-darwin"`. diff --git a/doc/manual/src/expressions/builtins-prefix.md b/doc/manual/src/language/builtins-prefix.md index c631a8453..c631a8453 100644 --- a/doc/manual/src/expressions/builtins-prefix.md +++ b/doc/manual/src/language/builtins-prefix.md diff --git a/doc/manual/src/expressions/builtins-suffix.md b/doc/manual/src/language/builtins-suffix.md index a74db2857..a74db2857 100644 --- a/doc/manual/src/expressions/builtins-suffix.md +++ b/doc/manual/src/language/builtins-suffix.md diff --git a/doc/manual/src/expressions/language-constructs.md b/doc/manual/src/language/constructs.md index 1c01f2cc7..1c01f2cc7 100644 --- a/doc/manual/src/expressions/language-constructs.md +++ b/doc/manual/src/language/constructs.md diff --git a/doc/manual/src/expressions/derivations.md b/doc/manual/src/language/derivations.md index d26a33b7f..043a38191 100644 --- a/doc/manual/src/expressions/derivations.md +++ b/doc/manual/src/language/derivations.md @@ -1,10 +1,10 @@ # Derivations The most important built-in function is `derivation`, which is used to -describe a single derivation (a build action). It takes as input a set, +describe a single derivation (a build task). It takes as input a set, the attributes of which specify the inputs of the build. - - There must be an attribute named `system` whose value must be a + - There must be an attribute named [`system`]{#attr-system} whose value must be a string specifying a Nix system type, such as `"i686-linux"` or `"x86_64-darwin"`. (To figure out your system type, run `nix -vv --version`.) The build can only be performed on a machine and diff --git a/doc/manual/src/language/index.md b/doc/manual/src/language/index.md new file mode 100644 index 000000000..db34fde75 --- /dev/null +++ b/doc/manual/src/language/index.md @@ -0,0 +1,581 @@ +# Nix Language + +The Nix language is + +- *domain-specific* + + It only exists for the Nix package manager: + to describe packages and configurations as well as their variants and compositions. + It is not intended for general purpose use. + +- *declarative* + + There is no notion of executing sequential steps. + Dependencies between operations are established only through data. + +- *pure* + + Values cannot change during computation. + Functions always produce the same output if their input does not change. + +- *functional* + + Functions are like any other value. + Functions can be assigned to names, taken as arguments, or returned by functions. + +- *lazy* + + Expressions are only evaluated when their value is needed. + +- *dynamically typed* + + Type errors are only detected when expressions are evaluated. + +# Overview + +This is an incomplete overview of language features, by example. + +<table> + <tr> + <th> + Example + </th> + <th> + Description + </th> + </tr> + <tr> + <td> + + + *Basic values* + + + </td> + <td> + + + + </td> + </tr> + <tr> + <td> + + `"hello world"` + + </td> + <td> + + A string + + </td> + </tr> + <tr> + <td> + + ``` + '' + multi + line + string + '' + ``` + + </td> + <td> + + A multi-line string. Strips common prefixed whitespace. Evaluates to `"multi\n line\n string"`. + + </td> + </tr> + <tr> + <td> + + `"hello ${ { a = "world" }.a }"` + + `"1 2 ${toString 3}"` + + `"${pkgs.bash}/bin/sh"` + + </td> + <td> + + String interpolation (expands to `"hello world"`, `"1 2 3"`, `"/nix/store/<hash>-bash-<version>/bin/sh"`) + + </td> + </tr> + <tr> + <td> + + `true`, `false` + + </td> + <td> + + Booleans + + </td> + </tr> + <tr> + <td> + + `null` + + </td> + <td> + + Null value + + </td> + </tr> + <tr> + <td> + + `123` + + </td> + <td> + + An integer + + </td> + </tr> + <tr> + <td> + + `3.141` + + </td> + <td> + + A floating point number + + </td> + </tr> + <tr> + <td> + + `/etc` + + </td> + <td> + + An absolute path + + </td> + </tr> + <tr> + <td> + + `./foo.png` + + </td> + <td> + + A path relative to the file containing this Nix expression + + </td> + </tr> + <tr> + <td> + + `~/.config` + + </td> + <td> + + A home path. Evaluates to the `"<user's home directory>/.config"`. + + </td> + </tr> + <tr> + <td> + + <nixpkgs> + + </td> + <td> + + Search path. Value determined by [`$NIX_PATH` environment variable](../command-ref/env-common.md#env-NIX_PATH). + + </td> + </tr> + <tr> + <td> + + *Compound values* + + </td> + <td> + + + + </td> + </tr> + <tr> + <td> + + `{ x = 1; y = 2; }` + + </td> + <td> + + A set with attributes named `x` and `y` + + </td> + </tr> + <tr> + <td> + + `{ foo.bar = 1; }` + + </td> + <td> + + A nested set, equivalent to `{ foo = { bar = 1; }; }` + + </td> + </tr> + <tr> + <td> + + `rec { x = "foo"; y = x + "bar"; }` + + </td> + <td> + + A recursive set, equivalent to `{ x = "foo"; y = "foobar"; }` + + </td> + </tr> + <tr> + <td> + + `[ "foo" "bar" "baz" ]` + + `[ 1 2 3 ]` + + `[ (f 1) { a = 1; b = 2; } [ "c" ] ]` + + </td> + <td> + + Lists with three elements. + + </td> + </tr> + <tr> + <td> + + *Operators* + + </td> + <td> + + + + </td> + </tr> + <tr> + <td> + + `"foo" + "bar"` + + </td> + <td> + + String concatenation + + </td> + </tr> + <tr> + <td> + + `1 + 2` + + </td> + <td> + + Integer addition + + </td> + </tr> + <tr> + <td> + + `"foo" == "f" + "oo"` + + </td> + <td> + + Equality test (evaluates to `true`) + + </td> + </tr> + <tr> + <td> + + `"foo" != "bar"` + + </td> + <td> + + Inequality test (evaluates to `true`) + + </td> + </tr> + <tr> + <td> + + `!true` + + </td> + <td> + + Boolean negation + + </td> + </tr> + <tr> + <td> + + `{ x = 1; y = 2; }.x` + + </td> + <td> + + Attribute selection (evaluates to `1`) + + </td> + </tr> + <tr> + <td> + + `{ x = 1; y = 2; }.z or 3` + + </td> + <td> + + Attribute selection with default (evaluates to `3`) + + </td> + </tr> + <tr> + <td> + + `{ x = 1; y = 2; } // { z = 3; }` + + </td> + <td> + + Merge two sets (attributes in the right-hand set taking precedence) + + </td> + </tr> + <tr> + <td> + + *Control structures* + + </td> + <td> + + + + </td> + </tr> + <tr> + <td> + + `if 1 + 1 == 2 then "yes!" else "no!"` + + </td> + <td> + + Conditional expression + + </td> + </tr> + <tr> + <td> + + `assert 1 + 1 == 2; "yes!"` + + </td> + <td> + + Assertion check (evaluates to `"yes!"`). + + </td> + </tr> + <tr> + <td> + + `let x = "foo"; y = "bar"; in x + y` + + </td> + <td> + + Variable definition + + </td> + </tr> + <tr> + <td> + + `with builtins; head [ 1 2 3 ]` + + </td> + <td> + + Add all attributes from the given set to the scope (evaluates to `1`) + + </td> + </tr> + <tr> + <td> + + *Functions (lambdas)* + + </td> + <td> + + + + </td> + </tr> + <tr> + <td> + + `x: x + 1` + + </td> + <td> + + A function that expects an integer and returns it increased by 1 + + </td> + </tr> + <tr> + <td> + + `x: y: x + y` + + </td> + <td> + + Curried function, equivalent to `x: (y: x + y)`. Can be used like a function that takes two arguments and returns their sum. + + </td> + </tr> + <tr> + <td> + + `(x: x + 1) 100` + + </td> + <td> + + A function call (evaluates to 101) + + </td> + </tr> + <tr> + <td> + + `let inc = x: x + 1; in inc (inc (inc 100))` + + </td> + <td> + + A function bound to a variable and subsequently called by name (evaluates to 103) + + </td> + </tr> + <tr> + <td> + + `{ x, y }: x + y` + + </td> + <td> + + A function that expects a set with required attributes `x` and `y` and concatenates them + + </td> + </tr> + <tr> + <td> + + `{ x, y ? "bar" }: x + y` + + </td> + <td> + + A function that expects a set with required attribute `x` and optional `y`, using `"bar"` as default value for `y` + + </td> + </tr> + <tr> + <td> + + `{ x, y, ... }: x + y` + + </td> + <td> + + A function that expects a set with required attributes `x` and `y` and ignores any other attributes + + </td> + </tr> + <tr> + <td> + + `{ x, y } @ args: x + y` + + `args @ { x, y }: x + y` + + </td> + <td> + + A function that expects a set with required attributes `x` and `y`, and binds the whole set to `args` + + </td> + </tr> + <tr> + <td> + + *Built-in functions* + + </td> + <td> + + + + </td> + </tr> + <tr> + <td> + + `import ./foo.nix` + + </td> + <td> + + Load and return Nix expression in given file + + </td> + </tr> + <tr> + <td> + + `map (x: x + x) [ 1 2 3 ]` + + </td> + <td> + + Apply a function to every element of a list (evaluates to `[ 2 4 6 ]`) + + </td> + </tr> +</table> diff --git a/doc/manual/src/language/operators.md b/doc/manual/src/language/operators.md new file mode 100644 index 000000000..797f13bd3 --- /dev/null +++ b/doc/manual/src/language/operators.md @@ -0,0 +1,167 @@ +# Operators + +| Name | Syntax | Associativity | Precedence | +|----------------------------------------|--------------------------------------------|---------------|------------| +| [Attribute selection] | *attrset* `.` *attrpath* \[ `or` *expr* \] | none | 1 | +| Function application | *func* *expr* | left | 2 | +| [Arithmetic negation][arithmetic] | `-` *number* | none | 3 | +| [Has attribute] | *attrset* `?` *attrpath* | none | 4 | +| List concatenation | *list* `++` *list* | right | 5 | +| [Multiplication][arithmetic] | *number* `*` *number* | left | 6 | +| [Division][arithmetic] | *number* `/` *number* | left | 6 | +| [Subtraction][arithmetic] | *number* `-` *number* | left | 7 | +| [Addition][arithmetic] | *number* `+` *number* | left | 7 | +| [String concatenation] | *string* `+` *string* | left | 7 | +| [Path concatenation] | *path* `+` *path* | left | 7 | +| [Path and string concatenation] | *path* `+` *string* | left | 7 | +| [String and path concatenation] | *string* `+` *path* | left | 7 | +| Logical negation (`NOT`) | `!` *bool* | none | 8 | +| [Update] | *attrset* `//` *attrset* | right | 9 | +| [Less than][Comparison] | *expr* `<` *expr* | none | 10 | +| [Less than or equal to][Comparison] | *expr* `<=` *expr* | none | 10 | +| [Greater than][Comparison] | *expr* `>` *expr* | none | 10 | +| [Greater than or equal to][Comparison] | *expr* `>=` *expr* | none | 10 | +| [Equality] | *expr* `==` *expr* | none | 11 | +| Inequality | *expr* `!=` *expr* | none | 11 | +| Logical conjunction (`AND`) | *bool* `&&` *bool* | left | 12 | +| Logical disjunction (`OR`) | *bool* `||` *bool* | left | 13 | +| [Logical implication] | *bool* `->` *bool* | none | 14 | + +[string]: ./values.md#type-string +[path]: ./values.md#type-path +[number]: ./values.md#type-number +[list]: ./values.md#list +[attribute set]: ./values.md#attribute-set + +## Attribute selection + +Select the attribute denoted by attribute path *attrpath* from [attribute set] *attrset*. +If the attribute doesn’t exist, return *value* if provided, otherwise abort evaluation. + +<!-- FIXME: the following should to into its own language syntax section, but that needs more work to fit in well --> + +An attribute path is a dot-separated list of attribute names. +An attribute name can be an identifier or a string. + +> *attrpath* = *name* [ `.` *name* ]... +> *name* = *identifier* | *string* +> *identifier* ~ `[a-zA-Z_][a-zA-Z0-9_'-]*` + +[Attribute selection]: #attribute-selection + +## Has attribute + +> *attrset* `?` *attrpath* + +Test whether [attribute set] *attrset* contains the attribute denoted by *attrpath*. +The result is a [Boolean] value. + +[Boolean]: ./values.md#type-boolean + +[Has attribute]: #has-attribute + +## Arithmetic + +Numbers are type-compatible: +Pure integer operations will always return integers, whereas any operation involving at least one floating point number return a floating point number. + +See also [Comparison] and [Equality]. + +The `+` operator is overloaded to also work on strings and paths. + +[arithmetic]: #arithmetic + +## String concatenation + +> *string* `+` *string* + +Concatenate two [string]s and merge their string contexts. + +[String concatenation]: #string-concatenation + +## Path concatenation + +> *path* `+` *path* + +Concatenate two [path]s. +The result is a path. + +[Path concatenation]: #path-concatenation + +## Path and string concatenation + +> *path* + *string* + +Concatenate *[path]* with *[string]*. +The result is a path. + +> **Note** +> +> The string must not have a string context that refers to a [store path]. + +[Path and string concatenation]: #path-and-string-concatenation + +## String and path concatenation + +> *string* + *path* + +Concatenate *[string]* with *[path]*. +The result is a string. + +> **Important** +> +> The file or directory at *path* must exist and is copied to the [store]. +> The path appears in the result as the corresponding [store path]. + +[store path]: ../glossary.md#gloss-store-path +[store]: ../glossary.md#gloss-store + +[Path and string concatenation]: #path-and-string-concatenation + +## Update + +> *attrset1* + *attrset2* + +Update [attribute set] *attrset1* with names and values from *attrset2*. + +The returned attribute set will have of all the attributes in *e1* and *e2*. +If an attribute name is present in both, the attribute value from the former is taken. + +[Update]: #update + +## Comparison + +Comparison is + +- [arithmetic] for [number]s +- lexicographic for [string]s and [path]s +- item-wise lexicographic for [list]s: + elements at the same index in both lists are compared according to their type and skipped if they are equal. + +All comparison operators are implemented in terms of `<`, and the following equivalencies hold: + +| comparison | implementation | +|--------------|-----------------------| +| *a* `<=` *b* | `! (` *b* `<` *a* `)` | +| *a* `>` *b* | *b* `<` *a* | +| *a* `>=` *b* | `! (` *a* `<` *b* `)` | + +[Comparison]: #comparison-operators + +## Equality + +- [Attribute sets][attribute set] and [list]s are compared recursively, and therefore are fully evaluated. +- Comparison of [function]s always returns `false`. +- Numbers are type-compatible, see [arithmetic] operators. +- Floating point numbers only differ up to a limited precision. + +[function]: ./constructs.md#functions + +[Equality]: #equality + +## Logical implication + +Equivalent to `!`*b1* `||` *b2*. + +[Logical implication]: #logical-implication + diff --git a/doc/manual/src/language/string-interpolation.md b/doc/manual/src/language/string-interpolation.md new file mode 100644 index 000000000..ddc6b8230 --- /dev/null +++ b/doc/manual/src/language/string-interpolation.md @@ -0,0 +1,82 @@ +# String interpolation + +String interpolation is a language feature where a [string], [path], or [attribute name] can contain expressions enclosed in `${ }` (dollar-sign with curly brackets). + +Such a string is an *interpolated string*, and an expression inside is an *interpolated expression*. + +Interpolated expressions must evaluate to one of the following: + +- a [string] +- a [path] +- a [derivation] + +[string]: ./values.md#type-string +[path]: ./values.md#type-path +[attribute name]: ./values.md#attribute-set +[derivation]: ../glossary.md#gloss-derivation + +## Examples + +### String + +Rather than writing + +```nix +"--with-freetype2-library=" + freetype + "/lib" +``` + +(where `freetype` is a [derivation]), you can instead write + +```nix +"--with-freetype2-library=${freetype}/lib" +``` + +The latter is automatically translated to the former. + +A more complicated example (from the Nix expression for [Qt](http://www.trolltech.com/products/qt)): + +```nix +configureFlags = " + -system-zlib -system-libpng -system-libjpeg + ${if openglSupport then "-dlopen-opengl + -L${mesa}/lib -I${mesa}/include + -L${libXmu}/lib -I${libXmu}/include" else ""} + ${if threadSupport then "-thread" else "-no-thread"} +"; +``` + +Note that Nix expressions and strings can be arbitrarily nested; +in this case the outer string contains various interpolated expressions that themselves contain strings (e.g., `"-thread"`), some of which in turn contain interpolated expressions (e.g., `${mesa}`). + +### Path + +Rather than writing + +```nix +./. + "/" + foo + "-" + bar + ".nix" +``` + +or + +```nix +./. + "/${foo}-${bar}.nix" +``` + +you can instead write + +```nix +./${foo}-${bar}.nix +``` + +### Attribute name + +Attribute names can be created dynamically with string interpolation: + +```nix +let name = "foo"; in +{ + ${name} = "bar"; +} +``` + + { foo = "bar"; } diff --git a/doc/manual/src/language/values.md b/doc/manual/src/language/values.md new file mode 100644 index 000000000..3973518ca --- /dev/null +++ b/doc/manual/src/language/values.md @@ -0,0 +1,251 @@ +# Data Types + +## Primitives + +- <a id="type-string" href="#type-string">String</a> + + *Strings* can be written in three ways. + + The most common way is to enclose the string between double quotes, + e.g., `"foo bar"`. Strings can span multiple lines. The special + characters `"` and `\` and the character sequence `${` must be + escaped by prefixing them with a backslash (`\`). Newlines, carriage + returns and tabs can be written as `\n`, `\r` and `\t`, + respectively. + + You can include the results of other expressions into a string by enclosing them in `${ }`, a feature known as [string interpolation]. + + [string interpolation]: ./string-interpolation.md + + The second way to write string literals is as an *indented string*, + which is enclosed between pairs of *double single-quotes*, like so: + + ```nix + '' + This is the first line. + This is the second line. + This is the third line. + '' + ``` + + This kind of string literal intelligently strips indentation from + the start of each line. To be precise, it strips from each line a + number of spaces equal to the minimal indentation of the string as a + whole (disregarding the indentation of empty lines). For instance, + the first and second line are indented two spaces, while the third + line is indented four spaces. Thus, two spaces are stripped from + each line, so the resulting string is + + ```nix + "This is the first line.\nThis is the second line.\n This is the third line.\n" + ``` + + Note that the whitespace and newline following the opening `''` is + ignored if there is no non-whitespace text on the initial line. + + Indented strings support [string interpolation]. + + Since `${` and `''` have special meaning in indented strings, you + need a way to quote them. `$` can be escaped by prefixing it with + `''` (that is, two single quotes), i.e., `''$`. `''` can be escaped + by prefixing it with `'`, i.e., `'''`. `$` removes any special + meaning from the following `$`. Linefeed, carriage-return and tab + characters can be written as `''\n`, `''\r`, `''\t`, and `''\` + escapes any other character. + + Indented strings are primarily useful in that they allow multi-line + string literals to follow the indentation of the enclosing Nix + expression, and that less escaping is typically necessary for + strings representing languages such as shell scripts and + configuration files because `''` is much less common than `"`. + Example: + + ```nix + stdenv.mkDerivation { + ... + postInstall = + '' + mkdir $out/bin $out/etc + cp foo $out/bin + echo "Hello World" > $out/etc/foo.conf + ${if enableBar then "cp bar $out/bin" else ""} + ''; + ... + } + ``` + + Finally, as a convenience, *URIs* as defined in appendix B of + [RFC 2396](http://www.ietf.org/rfc/rfc2396.txt) can be written *as + is*, without quotes. For instance, the string + `"http://example.org/foo.tar.bz2"` can also be written as + `http://example.org/foo.tar.bz2`. + +- <a id="type-number" href="#type-number">Number</a> + + Numbers, which can be *integers* (like `123`) or *floating point* + (like `123.43` or `.27e13`). + + See [arithmetic] and [comparison] operators for semantics. + + [arithmetic]: ./operators.md#arithmetic + [comparison]: ./operators.md#comparison + +- <a id="type-path" href="#type-path">Path</a> + + *Paths*, e.g., `/bin/sh` or `./builder.sh`. A path must contain at + least one slash to be recognised as such. For instance, `builder.sh` + is not a path: it's parsed as an expression that selects the + attribute `sh` from the variable `builder`. If the file name is + relative, i.e., if it does not begin with a slash, it is made + absolute at parse time relative to the directory of the Nix + expression that contained it. For instance, if a Nix expression in + `/foo/bar/bla.nix` refers to `../xyzzy/fnord.nix`, the absolute path + is `/foo/xyzzy/fnord.nix`. + + If the first component of a path is a `~`, it is interpreted as if + the rest of the path were relative to the user's home directory. + e.g. `~/foo` would be equivalent to `/home/edolstra/foo` for a user + whose home directory is `/home/edolstra`. + + Paths can also be specified between angle brackets, e.g. + `<nixpkgs>`. This means that the directories listed in the + environment variable `NIX_PATH` will be searched for the given file + or directory name. + + When an [interpolated string][string interpolation] evaluates to a path, the path is first copied into the Nix store and the resulting string is the [store path] of the newly created [store object]. + + [store path]: ../glossary.md#gloss-store-path + [store object]: ../glossary.md#gloss-store-object + + For instance, evaluating `"${./foo.txt}"` will cause `foo.txt` in the current directory to be copied into the Nix store and result in the string `"/nix/store/<hash>-foo.txt"`. + + Note that the Nix language assumes that all input files will remain _unchanged_ while evaluating a Nix expression. + For example, assume you used a file path in an interpolated string during a `nix repl` session. + Later in the same session, after having changed the file contents, evaluating the interpolated string with the file path again might not return a new store path, since Nix might not re-read the file contents. + + Paths themselves, except those in angle brackets (`< >`), support [string interpolation]. + + At least one slash (`/`) must appear *before* any interpolated expression for the result to be recognized as a path. + + `a.${foo}/b.${bar}` is a syntactically valid division operation. + `./a.${foo}/b.${bar}` is a path. + +- <a id="type-boolean" href="#type-boolean">Boolean</a> + + *Booleans* with values `true` and `false`. + +- <a id="type-null" href="#type-null">Null</a> + + The null value, denoted as `null`. + +## List + +Lists are formed by enclosing a whitespace-separated list of values +between square brackets. For example, + +```nix +[ 123 ./foo.nix "abc" (f { x = y; }) ] +``` + +defines a list of four elements, the last being the result of a call to +the function `f`. Note that function calls have to be enclosed in +parentheses. If they had been omitted, e.g., + +```nix +[ 123 ./foo.nix "abc" f { x = y; } ] +``` + +the result would be a list of five elements, the fourth one being a +function and the fifth being a set. + +Note that lists are only lazy in values, and they are strict in length. + +## Attribute Set + +An attribute set is a collection of name-value-pairs (called *attributes*) enclosed in curly brackets (`{ }`). + +Names and values are separated by an equal sign (`=`). +Each value is an arbitrary expression terminated by a semicolon (`;`). + +Attributes can appear in any order. +An attribute name may only occur once. + +Example: + +```nix +{ + x = 123; + text = "Hello"; + y = f { bla = 456; }; +} +``` + +This defines a set with attributes named `x`, `text`, `y`. + +Attributes can be selected from a set using the `.` operator. For +instance, + +```nix +{ a = "Foo"; b = "Bar"; }.a +``` + +evaluates to `"Foo"`. It is possible to provide a default value in an +attribute selection using the `or` keyword. For example, + +```nix +{ a = "Foo"; b = "Bar"; }.c or "Xyzzy" +``` + +will evaluate to `"Xyzzy"` because there is no `c` attribute in the set. + +You can use arbitrary double-quoted strings as attribute names: + +```nix +{ "$!@#?" = 123; }."$!@#?" +``` + +```nix +let bar = "bar"; +{ "foo ${bar}" = 123; }."foo ${bar}" +``` + +Both will evaluate to `123`. + +Attribute names support [string interpolation]: + +```nix +let bar = "foo"; in +{ foo = 123; }.${bar} +``` + +```nix +let bar = "foo"; in +{ ${bar} = 123; }.foo +``` + +Both will evaluate to `123`. + +In the special case where an attribute name inside of a set declaration +evaluates to `null` (which is normally an error, as `null` cannot be coerced to +a string), that attribute is simply not added to the set: + +```nix +{ ${if foo then "bar" else null} = true; } +``` + +This will evaluate to `{}` if `foo` evaluates to `false`. + +A set that has a `__functor` attribute whose value is callable (i.e. is +itself a function or a set with a `__functor` attribute whose value is +callable) can be applied as if it were a function, with the set itself +passed in first , e.g., + +```nix +let add = { __functor = self: x: x + self.x; }; + inc = add // { x = 1; }; +in inc 1 +``` + +evaluates to `2`. This can be used to attach metadata to a function +without the caller needing to treat it specially, or to implement a form +of object-oriented programming, for example. diff --git a/doc/manual/src/package-management/package-management.md b/doc/manual/src/package-management/package-management.md index bd26a09ab..d528112e2 100644 --- a/doc/manual/src/package-management/package-management.md +++ b/doc/manual/src/package-management/package-management.md @@ -1,5 +1,4 @@ This chapter discusses how to do package management with Nix, i.e., how to obtain, install, upgrade, and erase packages. This is the “user’s” perspective of the Nix system — people who want to *create* -packages should consult the [chapter on writing Nix -expressions](../expressions/writing-nix-expressions.md). +packages should consult the chapter on the [Nix language](../language/index.md). diff --git a/doc/manual/src/release-notes/rl-2.10.md b/doc/manual/src/release-notes/rl-2.10.md new file mode 100644 index 000000000..b99dbeef0 --- /dev/null +++ b/doc/manual/src/release-notes/rl-2.10.md @@ -0,0 +1,31 @@ +# Release 2.10 (2022-07-11) + +* `nix repl` now takes installables on the command line, unifying the usage + with other commands that use `--file` and `--expr`. Primary breaking change + is for the common usage of `nix repl '<nixpkgs>'` which can be recovered with + `nix repl --file '<nixpkgs>'` or `nix repl --expr 'import <nixpkgs>{}'`. + + This is currently guarded by the `repl-flake` experimental feature. + +* A new function `builtins.traceVerbose` is available. It is similar + to `builtins.trace` if the `trace-verbose` setting is set to true, + and it is a no-op otherwise. + +* `nix search` has a new flag `--exclude` to filter out packages. + +* On Linux, if `/nix` doesn't exist and cannot be created and you're + not running as root, Nix will automatically use + `~/.local/share/nix/root` as a chroot store. This enables non-root + users to download the statically linked Nix binary and have it work + out of the box, e.g. + + ``` + # ~/nix run nixpkgs#hello + warning: '/nix' does not exists, so Nix will use '/home/ubuntu/.local/share/nix/root' as a chroot store + Hello, world! + ``` + +* `flake-registry.json` is now fetched from `channels.nixos.org`. + +* Nix can now be built with LTO by passing `--enable-lto` to `configure`. + LTO is currently only supported when building with GCC. diff --git a/doc/manual/src/release-notes/rl-2.11.md b/doc/manual/src/release-notes/rl-2.11.md new file mode 100644 index 000000000..b322a4e5e --- /dev/null +++ b/doc/manual/src/release-notes/rl-2.11.md @@ -0,0 +1,5 @@ +# Release 2.11 (2022-08-24) + +* `nix copy` now copies the store paths in parallel as much as possible (again). + This doesn't apply for the `daemon` and `ssh-ng` stores which copy everything + in one batch to avoid latencies issues. diff --git a/doc/manual/src/release-notes/rl-2.12.md b/doc/manual/src/release-notes/rl-2.12.md new file mode 100644 index 000000000..e2045d7bf --- /dev/null +++ b/doc/manual/src/release-notes/rl-2.12.md @@ -0,0 +1,43 @@ +# Release 2.12 (2022-12-06) + +* On Linux, Nix can now run builds in a user namespace where they run + as root (UID 0) and have 65,536 UIDs available. + <!-- FIXME: move this to its own section about system features --> + This is primarily useful for running containers such as `systemd-nspawn` + inside a Nix build. For an example, see [`tests/systemd-nspawn/nix`][nspawn]. + + [nspawn]: https://github.com/NixOS/nix/blob/67bcb99700a0da1395fa063d7c6586740b304598/tests/systemd-nspawn.nix. + + A build can enable this by setting the derivation attribute: + + ``` + requiredSystemFeatures = [ "uid-range" ]; + ``` + + The `uid-range` [system feature] requires the [`auto-allocate-uids`] + setting to be enabled. + + [system feature]: ../command-ref/conf-file.md#conf-system-features + +* Nix can now automatically pick UIDs for builds, removing the need to + create `nixbld*` user accounts. See [`auto-allocate-uids`]. + + [`auto-allocate-uids`]: ../command-ref/conf-file.md#conf-auto-allocate-uids + +* On Linux, Nix has experimental support for running builds inside a + cgroup. See + [`use-cgroups`](../command-ref/conf-file.md#conf-use-cgroups). + +* `<nix/fetchurl.nix>` now accepts an additional argument `impure` which + defaults to `false`. If it is set to `true`, the `hash` and `sha256` + arguments will be ignored and the resulting derivation will have + `__impure` set to `true`, making it an impure derivation. + +* If `builtins.readFile` is called on a file with context, then only + the parts of the context that appear in the content of the file are + retained. This avoids a lot of spurious errors where strings end up + having a context just because they are read from a store path + ([#7260](https://github.com/NixOS/nix/pull/7260)). + +* `nix build --json` now prints some statistics about top-level + derivations, such as CPU statistics when cgroups are enabled. diff --git a/doc/manual/src/release-notes/rl-2.9.md b/doc/manual/src/release-notes/rl-2.9.md new file mode 100644 index 000000000..98cc4235d --- /dev/null +++ b/doc/manual/src/release-notes/rl-2.9.md @@ -0,0 +1,47 @@ +# Release 2.9 (2022-05-30) + +* Running Nix with the new `--debugger` flag will cause it to start a + repl session if an exception is thrown during evaluation, or if + `builtins.break` is called. From there you can inspect the values + of variables and evaluate Nix expressions. In debug mode, the + following new repl commands are available: + + ``` + :env Show env stack + :bt Show trace stack + :st Show current trace + :st <idx> Change to another trace in the stack + :c Go until end of program, exception, or builtins.break(). + :s Go one step + ``` + + Read more about the debugger + [here](https://www.zknotes.com/note/5970). + +* Nix now provides better integration with zsh's `run-help` + feature. It is now included in the Nix installation in the form of + an autoloadable shell function, `run-help-nix`. It picks up Nix + subcommands from the currently typed in command and directs the user + to the associated man pages. + +* `nix repl` has a new build-and-link (`:bl`) command that builds a + derivation while creating GC root symlinks. + +* The path produced by `builtins.toFile` is now allowed to be imported + or read even with restricted evaluation. Note that this will not + work with a read-only store. + +* `nix build` has a new `--print-out-paths` flag to print the + resulting output paths. This matches the default behaviour of + `nix-build`. + +* You can now specify which outputs of a derivation `nix` should + operate on using the syntax `installable^outputs`, + e.g. `nixpkgs#glibc^dev,static` or `nixpkgs#glibc^*`. By default, + `nix` will use the outputs specified by the derivation's + `meta.outputsToInstall` attribute if it exists, or all outputs + otherwise. + +* `builtins.fetchTree` (and flake inputs) can now be used to fetch + plain files over the `http(s)` and `file` protocols in addition to + directory tarballs. diff --git a/doc/manual/src/release-notes/rl-next.md b/doc/manual/src/release-notes/rl-next.md index c869b5e2f..9f491efc8 100644 --- a/doc/manual/src/release-notes/rl-next.md +++ b/doc/manual/src/release-notes/rl-next.md @@ -1 +1,23 @@ # Release X.Y (202?-??-??) + +* The `repeat` and `enforce-determinism` options have been removed + since they had been broken under many circumstances for a long time. + +* You can now use [flake references] in the [old command line interface], e.g. + + [flake references]: ../command-ref/new-cli/nix3-flake.md#flake-references + [old command line interface]: ../command-ref/main-commands.md + + ``` + # nix-build flake:nixpkgs -A hello + # nix-build -I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05 \ + '<nixpkgs>' -A hello + # NIX_PATH=nixpkgs=flake:nixpkgs nix-build '<nixpkgs>' -A hello + ``` + +* Instead of "antiquotation", the more common term [string interpolation](../language/string-interpolation.md) is now used consistently. + Historical release notes were not changed. + +* Error traces have been reworked to provide detailed explanations and more + accurate error locations. A short excerpt of the trace is now shown by + default when an error occurs. diff --git a/doc/manual/utils.nix b/doc/manual/utils.nix index d4b18472f..d0643ef46 100644 --- a/doc/manual/utils.nix +++ b/doc/manual/utils.nix @@ -5,6 +5,32 @@ rec { concatStrings = concatStringsSep ""; + replaceStringsRec = from: to: string: + # recursively replace occurrences of `from` with `to` within `string` + # example: + # replaceStringRec "--" "-" "hello-----world" + # => "hello-world" + let + replaced = replaceStrings [ from ] [ to ] string; + in + if replaced == string then string else replaceStringsRec from to replaced; + + squash = replaceStringsRec "\n\n\n" "\n\n"; + + trim = string: + # trim trailing spaces and squash non-leading spaces + let + trimLine = line: + let + # separate leading spaces from the rest + parts = split "(^ *)" line; + spaces = head (elemAt parts 1); + rest = elemAt parts 2; + # drop trailing spaces + body = head (split " *$" rest); + in spaces + replaceStringsRec " " " " body; + in concatStringsSep "\n" (map trimLine (splitLines string)); + # FIXME: O(n^2) unique = foldl' (acc: e: if elem e acc then acc else acc ++ [ e ]) []; |