diff options
| author | John Ericson <John.Ericson@Obsidian.Systems> | 2021-09-30 22:42:15 +0000 |
|---|---|---|
| committer | John Ericson <John.Ericson@Obsidian.Systems> | 2021-09-30 22:42:15 +0000 |
| commit | 9af9ab42126869b0be920db0224b7e1da58342a1 (patch) | |
| tree | 696cb996c35a75a15729f86ded875a0bcdffdc09 /doc/manual/src | |
| parent | d0ed11ca729344fd00251d0bc31f0c2f32d2c6a7 (diff) | |
| parent | f4f3203aa7c2fc9225a8ae220db25593066fb397 (diff) | |
Merge branch 'path-info' into ca-drv-exotic
Diffstat (limited to 'doc/manual/src')
22 files changed, 334 insertions, 455 deletions
diff --git a/doc/manual/src/SUMMARY.md.in b/doc/manual/src/SUMMARY.md.in index 448fee803..df9209c7d 100644 --- a/doc/manual/src/SUMMARY.md.in +++ b/doc/manual/src/SUMMARY.md.in @@ -70,6 +70,7 @@ - [Hacking](contributing/hacking.md) - [CLI guideline](contributing/cli-guideline.md) - [Release Notes](release-notes/release-notes.md) + - [Release 2.4 (2021-XX-XX)](release-notes/rl-2.4.md) - [Release 2.3 (2019-09-04)](release-notes/rl-2.3.md) - [Release 2.2 (2019-01-11)](release-notes/rl-2.2.md) - [Release 2.1 (2018-09-02)](release-notes/rl-2.1.md) diff --git a/doc/manual/src/advanced-topics/cores-vs-jobs.md b/doc/manual/src/advanced-topics/cores-vs-jobs.md index 4a9058ca1..9e91ab9c7 100644 --- a/doc/manual/src/advanced-topics/cores-vs-jobs.md +++ b/doc/manual/src/advanced-topics/cores-vs-jobs.md @@ -4,13 +4,13 @@ Nix has two relevant settings with regards to how your CPU cores will be utilized: `cores` and `max-jobs`. This chapter will talk about what they are, how they interact, and their configuration trade-offs. - - `max-jobs` + - `max-jobs`\ Dictates how many separate derivations will be built at the same time. If you set this to zero, the local machine will do no builds. Nix will still substitute from binary caches, and build remotely if remote builders are configured. - - `cores` + - `cores`\ Suggests how many cores each derivation should use. Similar to `make -j`. diff --git a/doc/manual/src/command-ref/env-common.md b/doc/manual/src/command-ref/env-common.md index c670d82b8..6e2403461 100644 --- a/doc/manual/src/command-ref/env-common.md +++ b/doc/manual/src/command-ref/env-common.md @@ -2,45 +2,49 @@ Most Nix commands interpret the following environment variables: - - `IN_NIX_SHELL` + - `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_PATH` + - `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 - + /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/nixos-15.09.tar.gz - - tells Nix to download the latest revision in the Nixpkgs/NixOS 15.09 - channel. - - A following shorthand can be used to refer to the official channels: - - nixpkgs=channel:nixos-15.09 - - The search path can be extended using the `-I` option, which takes - precedence over `NIX_PATH`. - - - `NIX_IGNORE_SYMLINK_STORE` + + 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`\ 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 @@ -50,7 +54,7 @@ Most Nix commands interpret the following environment variables: builds are deployed to machines where `/nix/store` resolves differently. If you are sure that you’re not going to do that, you can set `NIX_IGNORE_SYMLINK_STORE` to `1`. - + Note that if you’re symlinking the Nix store so that you can put it on another file system than the root file system, on Linux you’re better off using `bind` mount points, e.g., @@ -59,44 +63,44 @@ Most Nix commands interpret the following environment variables: $ mkdir /nix $ mount -o bind /mnt/otherdisk/nix /nix ``` - + Consult the mount 8 manual page for details. - - `NIX_STORE_DIR` + - `NIX_STORE_DIR`\ Overrides the location of the Nix store (default `prefix/store`). - - `NIX_DATA_DIR` + - `NIX_DATA_DIR`\ Overrides the location of the Nix static data directory (default `prefix/share`). - - `NIX_LOG_DIR` + - `NIX_LOG_DIR`\ Overrides the location of the Nix log directory (default `prefix/var/log/nix`). - - `NIX_STATE_DIR` + - `NIX_STATE_DIR`\ Overrides the location of the Nix state directory (default `prefix/var/nix`). - - `NIX_CONF_DIR` + - `NIX_CONF_DIR`\ Overrides the location of the system Nix configuration directory (default `prefix/etc/nix`). - - `NIX_CONFIG` + - `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`\ 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`\ 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`\ 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 @@ -104,16 +108,16 @@ 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`\ If set to `1`, Nix will print some evaluation statistics, such as the number of values allocated. - - `NIX_COUNT_CALLS` + - `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`\ 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 4565bfbc2..43de7a6e6 100644 --- a/doc/manual/src/command-ref/nix-build.md +++ b/doc/manual/src/command-ref/nix-build.md @@ -47,16 +47,16 @@ 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` + - `--no-out-link`\ 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`. - - `--dry-run` + - `--dry-run`\ Show what store paths would be built or downloaded. - - `--out-link` / `-o` *outlink* + - `--out-link` / `-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-channel.md b/doc/manual/src/command-ref/nix-channel.md index 4ca12d2cc..24353525f 100644 --- a/doc/manual/src/command-ref/nix-channel.md +++ b/doc/manual/src/command-ref/nix-channel.md @@ -17,26 +17,26 @@ To see the list of official NixOS channels, visit This command has the following operations: - - `--add` *url* \[*name*\] + - `--add` *url* \[*name*\]\ Adds a channel named *name* with URL *url* to the list of subscribed channels. If *name* is omitted, it defaults to the last component of *url*, with the suffixes `-stable` or `-unstable` removed. - - `--remove` *name* + - `--remove` *name*\ Removes the channel named *name* from the list of subscribed channels. - - `--list` + - `--list`\ Prints the names and URLs of all subscribed channels on standard output. - - `--update` \[*names*…\] + - `--update` \[*names*…\]\ Downloads the Nix expressions of all subscribed channels (or only those included in *names* if specified) and makes them the default for `nix-env` operations (by symlinking them from the directory `~/.nix-defexpr`). - - `--rollback` \[*generation*\] + - `--rollback` \[*generation*\]\ Reverts the previous call to `nix-channel --update`. Optionally, you can specify a specific channel generation number to restore. @@ -70,14 +70,14 @@ $ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version' # Files - - `/nix/var/nix/profiles/per-user/username/channels` + - `/nix/var/nix/profiles/per-user/username/channels`\ `nix-channel` uses a `nix-env` profile to keep track of previous versions of the subscribed channels. Every time you run `nix-channel --update`, a new channel generation (that is, a symlink to the channel Nix expressions in the Nix store) is created. This enables `nix-channel --rollback` to revert to previous versions. - - `~/.nix-defexpr/channels` + - `~/.nix-defexpr/channels`\ This is a symlink to `/nix/var/nix/profiles/per-user/username/channels`. It ensures that `nix-env` can find your channels. In a multi-user installation, you @@ -89,7 +89,7 @@ $ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version' A channel URL should point to a directory containing the following files: - - `nixexprs.tar.xz` + - `nixexprs.tar.xz`\ A tarball containing Nix expressions and files referenced by them (such as build scripts and patches). At the top level, the tarball should contain a single directory. That directory must contain a diff --git a/doc/manual/src/command-ref/nix-copy-closure.md b/doc/manual/src/command-ref/nix-copy-closure.md index dcb844a72..7047d3012 100644 --- a/doc/manual/src/command-ref/nix-copy-closure.md +++ b/doc/manual/src/command-ref/nix-copy-closure.md @@ -35,21 +35,21 @@ and second to send the dump of those paths. If this bothers you, use # Options - - `--to` + - `--to`\ Copy the closure of _paths_ from the local Nix store to the Nix store on _machine_. This is the default. - - `--from` + - `--from`\ Copy the closure of _paths_ from the Nix store on _machine_ to the local Nix store. - - `--gzip` + - `--gzip`\ Enable compression of the SSH connection. - - `--include-outputs` + - `--include-outputs`\ Also copy the outputs of store derivations included in the closure. - - `--use-substitutes` / `-s` + - `--use-substitutes` / `-s`\ Attempt to download missing paths on the target machine using Nix’s substitute mechanism. Any paths that cannot be substituted on the target are still copied normally from the source. This is useful, @@ -58,12 +58,12 @@ and second to send the dump of those paths. If this bothers you, use `nixos.org` (the default binary cache server) is fast. - - `-v` + - `-v`\ Show verbose output. # Environment variables - - `NIX_SSHOPTS` + - `NIX_SSHOPTS`\ Additional options to be passed to `ssh` on the command line. diff --git a/doc/manual/src/command-ref/nix-env.md b/doc/manual/src/command-ref/nix-env.md index 1c23bb0ad..9138fa05a 100644 --- a/doc/manual/src/command-ref/nix-env.md +++ b/doc/manual/src/command-ref/nix-env.md @@ -36,27 +36,27 @@ 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: - - `firefox` + - `firefox`\ Matches the package name `firefox` and any version. - - `firefox-32.0` + - `firefox-32.0`\ Matches the package name `firefox` and version `32.0`. - - `gtk\\+` + - `gtk\\+`\ Matches the package name `gtk+`. The `+` character must be escaped using a backslash to prevent it from being interpreted as a quantifier, and the backslash must be escaped in turn with another backslash to ensure that the shell passes it on. - - `.\*` + - `.\*`\ Matches any package name. This is the default for most commands. - - `'.*zip.*'` + - `'.*zip.*'`\ Matches any package name containing the string `zip`. Note the dots: `'*zip*'` does not work, because in a regular expression, the character `*` is interpreted as a quantifier. - - `'.*(firefox|chromium).*'` + - `'.*(firefox|chromium).*'`\ Matches any package name containing the strings `firefox` or `chromium`. @@ -66,7 +66,7 @@ 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. - - `--file` / `-f` *path* + - `--file` / `-f` *path*\ Specifies the Nix expression (designated below as the *active Nix expression*) used by the `--install`, `--upgrade`, and `--query --available` operations to obtain derivations. The default is @@ -77,13 +77,13 @@ have an effect. unpacked to a temporary location. The tarball must include a single top-level directory containing at least a file named `default.nix`. - - `--profile` / `-p` *path* + - `--profile` / `-p` *path*\ Specifies the profile to be used by those operations that operate on a profile (designated below as the *active profile*). A profile is a sequence of user environments called *generations*, one of which is the *current generation*. - - `--dry-run` + - `--dry-run`\ For the `--install`, `--upgrade`, `--uninstall`, `--switch-generation`, `--delete-generations` and `--rollback` operations, this flag will cause `nix-env` to print what *would* be @@ -93,7 +93,7 @@ have an effect. [substituted](../glossary.md) (i.e., downloaded) and which paths will be built from source (because no substitute is available). - - `--system-filter` *system* + - `--system-filter` *system*\ By default, operations such as `--query --available` show derivations matching any platform. This option allows you to use derivations for the specified platform *system*. @@ -102,7 +102,7 @@ have an effect. # Files - - `~/.nix-defexpr` + - `~/.nix-defexpr`\ The source for the default Nix expressions used by the `--install`, `--upgrade`, and `--query --available` operations to obtain derivations. The `--file` option may be used to override @@ -140,7 +140,7 @@ have an effect. The command `nix-channel` places symlinks to the downloaded Nix expressions from each subscribed channel in this directory. - - `~/.nix-profile` + - `~/.nix-profile`\ A symbolic link to the user's current profile. By default, this symlink points to `prefix/var/nix/profiles/default`. The `PATH` environment variable should include `~/.nix-profile/bin` for the @@ -217,13 +217,13 @@ a number of possible ways: ## Flags - - `--prebuilt-only` / `-b` + - `--prebuilt-only` / `-b`\ Use only derivations for which a substitute is registered, i.e., there is a pre-built binary available that can be downloaded in lieu of building the derivation. Thus, no packages will be built from source. - - `--preserve-installed`; `-P` + - `--preserve-installed`; `-P`\ Do not remove derivations with a name matching one of the derivations being installed. Usually, trying to have two versions of the same package installed in the same generation of a profile will @@ -231,7 +231,7 @@ a number of possible ways: clashes between the two versions. However, this is not the case for all packages. - - `--remove-all`; `-r` + - `--remove-all`; `-r`\ Remove all previously installed packages first. This is equivalent to running `nix-env -e '.*'` first, except that everything happens in a single transaction. @@ -346,24 +346,24 @@ version is installed. ## Flags - - `--lt` + - `--lt`\ Only upgrade a derivation to newer versions. This is the default. - - `--leq` + - `--leq`\ In addition to upgrading to newer versions, also “upgrade” to derivations that have the same version. Version are not a unique identification of a derivation, so there may be many derivations that have the same version. This flag may be useful to force “synchronisation” between the installed and available derivations. - - `--eq` + - `--eq`\ *Only* “upgrade” to derivations that have the same version. This may not seem very useful, but it actually is, e.g., when there is a new release of Nixpkgs and you want to replace installed applications with the same versions built against newer dependencies (to reduce the number of dependencies floating around on your system). - - `--always` + - `--always`\ In addition to upgrading to newer versions, also “upgrade” to derivations that have the same or a lower version. I.e., derivations may actually be downgraded depending on what is available in the @@ -578,11 +578,11 @@ The derivations are sorted by their `name` attributes. The following flags specify the set of things on which the query operates. - - `--installed` + - `--installed`\ The query operates on the store paths that are installed in the current generation of the active profile. This is the default. - - `--available`; `-a` + - `--available`; `-a`\ The query operates on the derivations that are available in the active Nix expression. @@ -593,24 +593,24 @@ selected derivations. Multiple flags may be specified, in which case the information is shown in the order given here. Note that the name of the derivation is shown unless `--no-name` is specified. - - `--xml` + - `--xml`\ Print the result in an XML representation suitable for automatic processing by other tools. The root element is called `items`, which contains a `item` element for each available or installed derivation. The fields discussed below are all stored in attributes of the `item` elements. - - `--json` + - `--json`\ Print the result in a JSON representation suitable for automatic processing by other tools. - - `--prebuilt-only` / `-b` + - `--prebuilt-only` / `-b`\ Show only derivations for which a substitute is registered, i.e., there is a pre-built binary available that can be downloaded in lieu of building the derivation. Thus, this shows all packages that probably can be installed quickly. - - `--status`; `-s` + - `--status`; `-s`\ Print the *status* of the derivation. The status consists of three characters. The first is `I` or `-`, indicating whether the derivation is currently installed in the current generation of the @@ -621,49 +621,49 @@ derivation is shown unless `--no-name` is specified. derivation to be built. The third is `S` or `-`, indicating whether a substitute is available for the derivation. - - `--attr-path`; `-P` + - `--attr-path`; `-P`\ Print the *attribute path* of the derivation, which can be used to unambiguously select it using the `--attr` option available in commands that install derivations like `nix-env --install`. This option only works together with `--available` - - `--no-name` + - `--no-name`\ Suppress printing of the `name` attribute of each derivation. - - `--compare-versions` / `-c` + - `--compare-versions` / `-c`\ Compare installed versions to available versions, or vice versa (if `--available` is given). This is useful for quickly seeing whether upgrades for installed packages are available in a Nix expression. A column is added with the following meaning: - - `<` *version* + - `<` *version*\ A newer version of the package is available or installed. - - `=` *version* + - `=` *version*\ At most the same version of the package is available or installed. - - `>` *version* + - `>` *version*\ Only older versions of the package are available or installed. - - `- ?` + - `- ?`\ No version of the package is available or installed. - - `--system` + - `--system`\ Print the `system` attribute of the derivation. - - `--drv-path` + - `--drv-path`\ Print the path of the store derivation. - - `--out-path` + - `--out-path`\ Print the output path of the derivation. - - `--description` + - `--description`\ Print a short (one-line) description of the derivation, if available. The description is taken from the `meta.description` attribute of the derivation. - - `--meta` + - `--meta`\ Print all of the meta-attributes of the derivation. This option is only available with `--xml` or `--json`. @@ -874,7 +874,7 @@ error: no generation older than the current (91) exists # Environment variables - - `NIX_PROFILE` + - `NIX_PROFILE`\ Location of the Nix profile. Defaults to the target of the symlink `~/.nix-profile`, if it exists, or `/nix/var/nix/profiles/default` otherwise. diff --git a/doc/manual/src/command-ref/nix-hash.md b/doc/manual/src/command-ref/nix-hash.md index de0459b9e..45f67f1c5 100644 --- a/doc/manual/src/command-ref/nix-hash.md +++ b/doc/manual/src/command-ref/nix-hash.md @@ -29,29 +29,29 @@ md5sum`. # Options - - `--flat` + - `--flat`\ Print the cryptographic hash of the contents of each regular file *path*. That is, do not compute the hash over the dump of *path*. The result is identical to that produced by the GNU commands `md5sum` and `sha1sum`. - - `--base32` + - `--base32`\ Print the hash in a base-32 representation rather than hexadecimal. This base-32 representation is more compact and can be used in Nix expressions (such as in calls to `fetchurl`). - - `--truncate` + - `--truncate`\ Truncate hashes longer than 160 bits (such as SHA-256) to 160 bits. - - `--type` *hashAlgo* + - `--type` *hashAlgo*\ Use the specified cryptographic hash algorithm, which can be one of `md5`, `sha1`, `sha256`, and `sha512`. - - `--to-base16` + - `--to-base16`\ Don’t hash anything, but convert the base-32 hash representation *hash* to hexadecimal. - - `--to-base32` + - `--to-base32`\ Don’t hash anything, but convert the hexadecimal hash representation *hash* to base-32. diff --git a/doc/manual/src/command-ref/nix-instantiate.md b/doc/manual/src/command-ref/nix-instantiate.md index c369397b6..2e198daed 100644 --- a/doc/manual/src/command-ref/nix-instantiate.md +++ b/doc/manual/src/command-ref/nix-instantiate.md @@ -29,26 +29,26 @@ standard input. # Options - - `--add-root` *path* + - `--add-root` *path*\ See the [corresponding option](nix-store.md) in `nix-store`. - - `--parse` + - `--parse`\ Just parse the input files, and print their abstract syntax trees on standard output in ATerm format. - - `--eval` + - `--eval`\ Just parse and evaluate the input files, and print the resulting values on standard output. No instantiation of store derivations takes place. - - `--find-file` + - `--find-file`\ Look up the given files in Nix’s search path (as specified by the `NIX_PATH` environment variable). If found, print the corresponding absolute paths on standard output. For instance, if `NIX_PATH` is `nixpkgs=/home/alice/nixpkgs`, then `nix-instantiate --find-file nixpkgs/default.nix` will print `/home/alice/nixpkgs/default.nix`. - - `--strict` + - `--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). @@ -58,17 +58,17 @@ standard input. > This option can cause non-termination, because lazy data > structures can be infinitely large. - - `--json` + - `--json`\ When used with `--eval`, print the resulting value as an JSON representation of the abstract syntax tree rather than as an ATerm. - - `--xml` + - `--xml`\ 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). - - `--read-write-mode` + - `--read-write-mode`\ When used with `--eval`, perform evaluation in read/write mode so nix language features that require it will still work (at the cost of needing to do instantiation of every evaluated derivation). If diff --git a/doc/manual/src/command-ref/nix-prefetch-url.md b/doc/manual/src/command-ref/nix-prefetch-url.md index 59ab89b29..3bcd209e2 100644 --- a/doc/manual/src/command-ref/nix-prefetch-url.md +++ b/doc/manual/src/command-ref/nix-prefetch-url.md @@ -37,22 +37,22 @@ Nix store is also printed. # Options - - `--type` *hashAlgo* + - `--type` *hashAlgo*\ Use the specified cryptographic hash algorithm, which can be one of `md5`, `sha1`, `sha256`, and `sha512`. - - `--print-path` + - `--print-path`\ Print the store path of the downloaded file on standard output. - - `--unpack` + - `--unpack`\ Unpack the archive (which must be a tarball or zip file) and add the result to the Nix store. The resulting hash can be used with functions such as Nixpkgs’s `fetchzip` or `fetchFromGitHub`. - - `--executable` + - `--executable`\ Set the executable bit on the downloaded file. - - `--name` *name* + - `--name` *name*\ Override the name of the file in the Nix store. By default, this is `hash-basename`, where *basename* is the last component of *url*. Overriding the name is necessary when *basename* contains characters diff --git a/doc/manual/src/command-ref/nix-shell.md b/doc/manual/src/command-ref/nix-shell.md index 54812a49f..72f6730f1 100644 --- a/doc/manual/src/command-ref/nix-shell.md +++ b/doc/manual/src/command-ref/nix-shell.md @@ -54,7 +54,7 @@ All options not listed here are passed to `nix-store --realise`, except for `--arg` and `--attr` / `-A` which are passed to `nix-instantiate`. - - `--command` *cmd* + - `--command` *cmd*\ In the environment of the derivation, run the shell command *cmd*. This command is executed in an interactive shell. (Use `--run` to use a non-interactive shell instead.) However, a call to `exit` is @@ -64,36 +64,34 @@ All options not listed here are passed to `nix-store drop you into the interactive shell. This can be useful for doing any additional initialisation. - - `--run` *cmd* + - `--run` *cmd*\ Like `--command`, but executes the command in a non-interactive shell. This means (among other things) that if you hit Ctrl-C while the command is running, the shell exits. - - `--exclude` *regexp* + - `--exclude` *regexp*\ Do not build any dependencies whose store path matches the regular expression *regexp*. This option may be specified multiple times. - - `--pure` + - `--pure`\ If this flag is specified, the environment is almost entirely cleared before the interactive shell is started, so you get an environment that more closely corresponds to the “real” Nix build. A few variables, in particular `HOME`, `USER` and `DISPLAY`, are - retained. Note that (depending on your Bash - installation) `/etc/bashrc` is still sourced, so any variables set - there will affect the interactive shell. + retained. - - `--packages` / `-p` *packages*… + - `--packages` / `-p` *packages*…\ Set up an environment in which the specified packages are present. The command line arguments are interpreted as attribute names inside the Nix Packages collection. Thus, `nix-shell -p libjpeg openjdk` will start a shell in which the packages denoted by the attribute names `libjpeg` and `openjdk` are present. - - `-i` *interpreter* + - `-i` *interpreter*\ The chained script interpreter to be invoked by `nix-shell`. Only applicable in `#!`-scripts (described below). - - `--keep` *name* + - `--keep` *name*\ When a `--pure` shell is started, keep the listed environment variables. @@ -101,7 +99,7 @@ The following common options are supported: # Environment variables - - `NIX_BUILD_SHELL` + - `NIX_BUILD_SHELL`\ Shell used to start the interactive environment. Defaults to the `bash` found in `PATH`. diff --git a/doc/manual/src/command-ref/nix-store.md b/doc/manual/src/command-ref/nix-store.md index 49d06f31e..7a131dc02 100644 --- a/doc/manual/src/command-ref/nix-store.md +++ b/doc/manual/src/command-ref/nix-store.md @@ -22,7 +22,7 @@ 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* + - `--add-root` *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 @@ -86,15 +86,15 @@ non-derivations argument, the argument itself is printed.) The following flags are available: - - `--dry-run` + - `--dry-run`\ Print on standard error a description of what packages would be built or downloaded, without actually performing the operation. - - `--ignore-unknown` + - `--ignore-unknown`\ If a non-derivation path does not have a substitute, then silently ignore it. - - `--check` + - `--check`\ This option allows you to check whether a derivation is deterministic. It rebuilds the specified derivation and checks whether the result is bitwise-identical with the existing outputs, @@ -110,20 +110,20 @@ The following flags are available: Special exit codes: - - `100` + - `100`\ Generic build failure, the builder process returned with a non-zero exit code. - - `101` + - `101`\ Build timeout, the build was aborted because it did not complete within the specified `timeout`. - - `102` + - `102`\ Hash mismatch, the build output was rejected because it does not match the [`outputHash` attribute of the derivation](../expressions/advanced-attributes.md). - - `104` + - `104`\ Not deterministic, the build succeeded in check mode but the resulting output is not binary reproducable. @@ -170,7 +170,7 @@ access to a restricted ssh user. The following flags are available: - - `--write` + - `--write`\ Allow the connected client to request the realization of derivations. In effect, this can be used to make the host act as a remote builder. @@ -200,18 +200,18 @@ reachable via file system references from a set of “roots”, are deleted. The following suboperations may be specified: - - `--print-roots` + - `--print-roots`\ This operation prints on standard output the set of roots used by the garbage collector. - - `--print-live` + - `--print-live`\ This operation prints on standard output the set of “live” store paths, which are all the store paths reachable from the roots. Live paths should never be deleted, since that would break consistency — it would become possible that applications are installed that reference things that are no longer present in the store. - - `--print-dead` + - `--print-dead`\ This operation prints out on standard output the set of “dead” store paths, which is just the opposite of the set of live paths: any path in the store that is not live (with respect to the roots) is dead. @@ -219,7 +219,7 @@ The following suboperations may be specified: By default, all unreachable paths are deleted. The following options control what gets deleted and in what order: - - `--max-freed` *bytes* + - `--max-freed` *bytes*\ Keep deleting paths until at least *bytes* bytes have been deleted, then stop. The argument *bytes* can be followed by the multiplicative suffix `K`, `M`, `G` or `T`, denoting KiB, MiB, GiB @@ -300,22 +300,22 @@ symlink. ## Common query options - - `--use-output`; `-u` + - `--use-output`; `-u`\ 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` + - `--force-realise`; `-f`\ Realise each argument to the query first (see [`nix-store --realise`](#operation---realise)). ## Queries - - `--outputs` + - `--outputs`\ Prints out the [output paths](../glossary.md) of the store derivations *paths*. These are the paths that will be produced when the derivation is built. - - `--requisites`; `-R` + - `--requisites`; `-R`\ Prints out the [closure](../glossary.md) of the store path *paths*. This query has one option: @@ -332,31 +332,31 @@ symlink. dependencies) is obtained by distributing the closure of a store derivation and specifying the option `--include-outputs`. - - `--references` + - `--references`\ Prints the set of [references](../glossary.md) of the store paths *paths*, that is, their immediate dependencies. (For *all* dependencies, use `--requisites`.) - - `--referrers` + - `--referrers`\ Prints the set of *referrers* of the store paths *paths*, that is, the store paths currently existing in the Nix store that refer to one of *paths*. Note that contrary to the references, the set of referrers is not constant; it can change as store paths are added or removed. - - `--referrers-closure` + - `--referrers-closure`\ Prints the closure of the set of store paths *paths* under the referrers relation; that is, all store paths that directly or indirectly refer to one of *paths*. These are all the path currently in the Nix store that are dependent on *paths*. - - `--deriver`; `-d` + - `--deriver`; `-d`\ Prints the [deriver](../glossary.md) of the store paths *paths*. If the path has no deriver (e.g., if it is a source file), or if the deriver is not known (e.g., in the case of a binary-only deployment), the string `unknown-deriver` is printed. - - `--graph` + - `--graph`\ Prints the references graph of the store paths *paths* in the format of the `dot` tool of AT\&T's [Graphviz package](http://www.graphviz.org/). This can be used to visualise @@ -364,39 +364,39 @@ symlink. this to a store derivation. To obtain a runtime dependency graph, apply it to an output path. - - `--tree` + - `--tree`\ Prints the references graph of the store paths *paths* as a nested ASCII tree. References are ordered by descending closure size; this tends to flatten the tree, making it more readable. The query only recurses into a store path when it is first encountered; this prevents a blowup of the tree representation of the graph. - - `--graphml` + - `--graphml`\ 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 runtime dependency graph, apply it to an output path. - - `--binding` *name*; `-b` *name* + - `--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 derivation to not have the specified attribute. - - `--hash` + - `--hash`\ Prints the SHA-256 hash of the contents of the store paths *paths* (that is, the hash of the output of `nix-store --dump` on the given paths). Since the hash is stored in the Nix database, this is a fast operation. - - `--size` + - `--size`\ Prints the size in bytes of the contents of the store paths *paths* — to be precise, the size of the output of `nix-store --dump` on the given paths. Note that the actual disk space required by the store paths may be higher, especially on filesystems with large cluster sizes. - - `--roots` + - `--roots`\ Prints the garbage collector roots that point, directly or indirectly, at the store paths *paths*. @@ -513,7 +513,7 @@ public url or broke since the download expression was written. This operation has the following options: - - `--recursive` + - `--recursive`\ Use recursive instead of flat hashing mode, used when adding directories to the store. @@ -540,14 +540,14 @@ being modified by non-Nix tools, or of bugs in Nix itself. This operation has the following options: - - `--check-contents` + - `--check-contents`\ Checks that the contents of every valid store path has not been altered by computing a SHA-256 hash of the contents and comparing it with the hash stored in the Nix database at build time. Paths that have been modified are printed out. For large stores, `--check-contents` is obviously quite slow. - - `--repair` + - `--repair`\ If any valid path is missing from the store, or (if `--check-contents` is given) the contents of a valid path has been modified, then try to repair the path by redownloading it. See diff --git a/doc/manual/src/command-ref/opt-common.md b/doc/manual/src/command-ref/opt-common.md index bc8eb6796..47862bc09 100644 --- a/doc/manual/src/command-ref/opt-common.md +++ b/doc/manual/src/command-ref/opt-common.md @@ -2,56 +2,56 @@ Most Nix commands accept the following command-line options: - - `--help` + - `--help`\ Prints out a summary of the command syntax and exits. - - `--version` + - `--version`\ Prints out the Nix version number on standard output and exits. - - `--verbose` / `-v` + - `--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 printed on standard error, never on standard output. - + This option may be specified repeatedly. Currently, the following verbosity levels exist: - - - 0 + + - 0\ “Errors only”: only print messages explaining why the Nix invocation failed. - - - 1 + + - 1\ “Informational”: print *useful* messages about what Nix is doing. This is the default. - - - 2 + + - 2\ “Talkative”: print more informational messages. - - - 3 + + - 3\ “Chatty”: print even more informational messages. - - - 4 + + - 4\ “Debug”: print debug information. - - - 5 + + - 5\ “Vomit”: print vast amounts of debug information. - - `--quiet` + - `--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` *format*\ This option can be used to change the output of the log format, with *format* being one of: - - - raw + + - raw\ This is the raw format, as outputted by nix-build. - - - internal-json + + - internal-json\ Outputs the logs in a structured manner. > **Warning** @@ -60,30 +60,30 @@ Most Nix commands accept the following command-line options: > the error-messages (namely of the `msg`-field) can change > between releases. - - bar + - bar\ Only display a progress bar during the builds. - - - bar-with-logs + + - bar-with-logs\ Display the raw logs, with the progress bar at the bottom. - - `--no-build-output` / `-Q` + - `--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` / `-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` configuration setting, which itself defaults to `1`. A higher value is useful on SMP systems or to exploit I/O latency. - + 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`\ 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`\ 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`\ 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` / `-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 @@ -113,17 +113,17 @@ 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` / `-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`\ 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. - + The most common scenario in which this is useful is when we have registered substitutes in order to perform binary distribution from, say, a network repository. If the repository is down, the @@ -134,12 +134,12 @@ 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`\ 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` *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 @@ -151,7 +151,7 @@ Most Nix commands accept the following command-line options: override a default value). That is, if the evaluator encounters a function with an argument named *name*, it will call it with value *value*. - + For instance, the top-level `default.nix` in Nixpkgs is actually a function: @@ -161,7 +161,7 @@ Most Nix commands accept the following command-line options: ... }: ... ``` - + So if you call this Nix expression (e.g., when you do `nix-env -i pkgname`), the function will be called automatically using the value [`builtins.currentSystem`](../expressions/builtins.md) for @@ -170,13 +170,13 @@ Most Nix commands accept the following command-line options: since the argument is a Nix string literal, you have to escape the quotes.) - - `--argstr` *name* *value* + - `--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` / `-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 @@ -185,34 +185,34 @@ Most Nix commands accept the following command-line options: would cause the expression `e.xorg.xorgserver` to be used. See [`nix-env --install`](nix-env.md#operation---install) for some concrete examples. - + In addition to attribute names, you can also specify array indices. For instance, the attribute path `foo.3.bar` selects the `bar` attribute of the fourth element of the array in the `foo` attribute of the top-level expression. - - `--expr` / `-E` + - `--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.) - + For `nix-shell`, this option is commonly used to give you a shell in which you can build the packages returned by the expression. If you want to get a shell which contain the *built* packages ready for use, give your expression to the `nix-shell -p` convenience flag instead. - - `-I` *path* + - `-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` *name* *value*\ Set the Nix configuration option *name* to *value*. This overrides settings in the Nix configuration file (see nix.conf5). - - `--repair` + - `--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/expressions/advanced-attributes.md b/doc/manual/src/expressions/advanced-attributes.md index 31ebadda1..5b208df67 100644 --- a/doc/manual/src/expressions/advanced-attributes.md +++ b/doc/manual/src/expressions/advanced-attributes.md @@ -2,14 +2,14 @@ Derivations can declare some infrequently used optional attributes. - - `allowedReferences` + - `allowedReferences`\ The optional attribute `allowedReferences` specifies a list of legal references (dependencies) of the output of the builder. For example, - + ```nix allowedReferences = []; ``` - + enforces that the output of a derivation cannot have any runtime dependencies on its inputs. To allow an output to have a runtime dependency on itself, use `"out"` as a list item. This is used in @@ -17,45 +17,45 @@ Derivations can declare some infrequently used optional attributes. booting Linux don’t have accidental dependencies on other paths in the Nix store. - - `allowedRequisites` + - `allowedRequisites`\ This attribute is similar to `allowedReferences`, but it specifies the legal requisites of the whole closure, so all the dependencies recursively. For example, - + ```nix allowedRequisites = [ foobar ]; ``` - + enforces that the output of a derivation cannot have any other runtime dependency than `foobar`, and in addition it enforces that `foobar` itself doesn't introduce any other dependency itself. - - `disallowedReferences` + - `disallowedReferences`\ The optional attribute `disallowedReferences` specifies a list of illegal references (dependencies) of the output of the builder. For example, - + ```nix disallowedReferences = [ foo ]; ``` - + enforces that the output of a derivation cannot have a direct runtime dependencies on the derivation `foo`. - - `disallowedRequisites` + - `disallowedRequisites`\ This attribute is similar to `disallowedReferences`, but it specifies illegal requisites for the whole closure, so all the dependencies recursively. For example, - + ```nix disallowedRequisites = [ foobar ]; ``` - + enforces that the output of a derivation cannot have any runtime dependency on `foobar` or any other derivation depending recursively on `foobar`. - - `exportReferencesGraph` + - `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 @@ -65,17 +65,17 @@ Derivations can declare some infrequently used optional attributes. files have the format used by `nix-store --register-validity` (with the deriver fields left empty). For example, when the following derivation is built: - + ```nix derivation { ... exportReferencesGraph = [ "libfoo-graph" libfoo ]; }; ``` - + the references graph of `libfoo` is placed in the file `libfoo-graph` in the temporary build directory. - + `exportReferencesGraph` is useful for builders that want to do something with the closure of a store path. Examples include the builders in NixOS that generate the initial ramdisk for booting @@ -84,66 +84,66 @@ Derivations can declare some infrequently used optional attributes. with a Nix store containing the closure of a bootable NixOS configuration). - - `impureEnvVars` + - `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 builder is executed, but with this attribute you can allow specific environment variables to be passed unmodified. For example, `fetchurl` in Nixpkgs has the line - + ```nix impureEnvVars = [ "http_proxy" "https_proxy" ... ]; ``` - + to make it use the proxy server configuration specified by the user in the environment variables `http_proxy` and friends. - + This attribute is only allowed in *fixed-output derivations* (see below), where impurities such as these are okay since (the hash of) the output is known in advance. It is ignored for all other derivations. - + > **Warning** - > + > > `impureEnvVars` implementation takes environment variables from > the current builder process. When a daemon is building its > environmental variables are used. Without the daemon, the > environmental variables come from the environment of the > `nix-build`. - - `outputHash`; `outputHashAlgo`; `outputHashMode` + - `outputHash`; `outputHashAlgo`; `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 fixed-output derivation finishes, Nix computes the cryptographic hash of the output and compares it to the hash declared with these attributes. If there is a mismatch, the build fails. - + The rationale for fixed-output derivations is derivations such as those produced by the `fetchurl` function. This function downloads a file from a given URL. To ensure that the downloaded file has not been modified, the caller must also specify a cryptographic hash of the file. For example, - + ```nix fetchurl { url = "http://ftp.gnu.org/pub/gnu/hello/hello-2.1.1.tar.gz"; sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465"; } ``` - + It sometimes happens that the URL of the file changes, e.g., because servers are reorganised or no longer available. We then must update the call to `fetchurl`, e.g., - + ```nix fetchurl { url = "ftp://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz"; sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465"; } ``` - + If a `fetchurl` derivation was treated like a normal derivation, the output paths of the derivation and *all derivations depending on it* would change. For instance, if we were to change the URL of the @@ -151,16 +151,16 @@ Derivations can declare some infrequently used optional attributes. other packages depend) massive rebuilds would be needed. This is unfortunate for a change which we know cannot have a real effect as it propagates upwards through the dependency graph. - + For fixed-output derivations, on the other hand, the name of the output path only depends on the `outputHash*` and `name` attributes, while all other attributes are ignored for the purpose of computing the output path. (The `name` attribute is included because it is part of the path.) - + As an example, here is the (simplified) Nix expression for `fetchurl`: - + ```nix { stdenv, curl }: # The curl program is used for downloading. @@ -180,43 +180,51 @@ Derivations can declare some infrequently used optional attributes. inherit url; } ``` - + The `outputHashAlgo` attribute specifies the hash algorithm used to compute the hash. It can currently be `"sha1"`, `"sha256"` or `"sha512"`. - + The `outputHashMode` attribute determines how the hash is computed. It must be one of the following two values: - - - `"flat"` + + - `"flat"`\ The output must be a non-executable regular file. If it isn’t, the build fails. The hash is simply computed over the contents of that file (so it’s equal to what Unix commands like `sha256sum` or `sha1sum` produce). - + This is the default. - - - `"recursive"` + + - `"recursive"`\ The hash is computed over the NAR archive dump of the output (i.e., the result of [`nix-store --dump`](../command-ref/nix-store.md#operation---dump)). In this case, the output can be anything, including a directory tree. - + The `outputHash` attribute, finally, must be a string containing the hash in either hexadecimal or base-32 notation. (See the [`nix-hash` command](../command-ref/nix-hash.md) for information about converting to and from base-32 notation.) + + - `__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. + This only has an effect if the `ca-derivation` experimental feature is enabled. + + Setting this attribute also requires setting `outputHashMode` and `outputHashAlgo` like for *fixed-output derivations* (see above). - - `passAsFile` + - `passAsFile`\ A list of names of attributes that should be passed via files rather than environment variables. For example, if you have - + ```nix passAsFile = ["big"]; big = "a very long string"; ``` - + then when the builder runs, the environment variable `bigPath` will contain the absolute path to a temporary file containing `a very long string`. That is, for any attribute *x* listed in @@ -226,7 +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`\ If this attribute is set to `true` and [distributed building is enabled](../advanced-topics/distributed-builds.md), then, if possible, the derivaton will be built locally instead of forwarded @@ -234,14 +242,14 @@ 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`\ 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) that are cheaper to build than to substitute from a binary cache. - + > **Note** - > + > > You need to have a builder configured which satisfies the > derivation’s `system` attribute, since the derivation cannot be > substituted. Thus it is usually a good idea to align `system` with diff --git a/doc/manual/src/expressions/builtin-constants.md b/doc/manual/src/expressions/builtin-constants.md index 3345a715b..1404289e5 100644 --- a/doc/manual/src/expressions/builtin-constants.md +++ b/doc/manual/src/expressions/builtin-constants.md @@ -2,7 +2,7 @@ Here are the constants built into the Nix expression evaluator: - - `builtins` + - `builtins`\ The set `builtins` contains all the built-in functions and values. You can use `builtins` to test for the availability of features in the Nix installation, e.g., @@ -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`\ 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/expressions/builtins-prefix.md index 0f7c3d32f..87127de2a 100644 --- a/doc/manual/src/expressions/builtins-prefix.md +++ b/doc/manual/src/expressions/builtins-prefix.md @@ -9,7 +9,8 @@ scope. Instead, you can access them through the `builtins` built-in value, which is a set that contains all built-in functions and values. For instance, `derivation` is also available as `builtins.derivation`. - - `derivation` *attrs*; `builtins.derivation` *attrs* - - `derivation` is described in [its own section](derivations.md). - +<dl> + <dt><code>derivation <var>attrs</var></code>; + <code>builtins.derivation <var>attrs</var></code></dt> + <dd><p><var>derivation</var> in described in + <a href="derivations.md">its own section</a>.</p></dd> diff --git a/doc/manual/src/expressions/builtins-suffix.md b/doc/manual/src/expressions/builtins-suffix.md new file mode 100644 index 000000000..a74db2857 --- /dev/null +++ b/doc/manual/src/expressions/builtins-suffix.md @@ -0,0 +1 @@ +</dl> diff --git a/doc/manual/src/expressions/language-values.md b/doc/manual/src/expressions/language-values.md index ce31029cc..28fa23b58 100644 --- a/doc/manual/src/expressions/language-values.md +++ b/doc/manual/src/expressions/language-values.md @@ -139,6 +139,13 @@ Nix has the following basic data types: 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`. diff --git a/doc/manual/src/glossary.md b/doc/manual/src/glossary.md index 56af9cd85..bb350d9de 100644 --- a/doc/manual/src/glossary.md +++ b/doc/manual/src/glossary.md @@ -1,48 +1,48 @@ # Glossary - - derivation + - derivation\ A description of a build action. 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 translated into low-level *store derivations* (implicitly by `nix-env` and `nix-build`, or explicitly by `nix-instantiate`). - - store + - store\ The location in the file system where store objects live. Typically `/nix/store`. - - store path + - store path\ The location in the file system of a store object, i.e., an immediate child of the Nix store directory. - - store object + - 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). - - substitute + - 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 + - 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\ 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\ 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 +52,11 @@ output paths), whereas an output path only references other output paths. - - reachable + - reachable\ A store path `Q` is reachable from another store path `P` if `Q` is in the *closure* of the *references* relation. - - closure + - 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 @@ -71,29 +71,29 @@ 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 + - output path\ A store path produced by a derivation. - - deriver + - deriver\ The deriver of an *output path* is the store derivation that built it. - - validity + - 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\ 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*. - - profile + - profile\ A symlink to the current *user environment* of a user, e.g., `/nix/var/nix/profiles/default`. - - NAR + - 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` diff --git a/doc/manual/src/installation/installing-binary.md b/doc/manual/src/installation/installing-binary.md index ae7fd458b..96fa34635 100644 --- a/doc/manual/src/installation/installing-binary.md +++ b/doc/manual/src/installation/installing-binary.md @@ -1,18 +1,26 @@ # Installing a Binary Distribution -If you are using Linux or macOS versions up to 10.14 (Mojave), the -easiest way to install Nix is to run the following command: +The easiest way to install Nix is to run the following command: ```console $ sh <(curl -L https://nixos.org/nix/install) ``` -If you're using macOS 10.15 (Catalina) or newer, consult [the macOS -installation instructions](#macos-installation) before installing. +This will run the installer interactively (causing it to explain what +it is doing more explicitly), and perform the default "type" of install +for your platform: +- single-user on Linux +- multi-user on macOS -As of Nix 2.1.0, the Nix installer will always default to creating a -single-user installation, however opting in to the multi-user -installation is highly recommended. + > **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 + > as single-user, so this type is no longer supported on macOS. + +We recommend the multi-user install if it supports your platform and +you can authenticate with `sudo`. # Single User Installation @@ -50,9 +58,9 @@ $ rm -rf /nix The multi-user Nix installation creates system users, and a system service for the Nix daemon. - - Linux running systemd, with SELinux disabled - - - macOS +**Supported Systems** +- Linux running systemd, with SELinux disabled +- macOS You can instruct the installer to perform a multi-user installation on your system: @@ -96,165 +104,28 @@ sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist There may also be references to Nix in `/etc/profile`, `/etc/bashrc`, and `/etc/zshrc` which you may remove. -# macOS Installation - -Starting with macOS 10.15 (Catalina), the root filesystem is read-only. -This means `/nix` can no longer live on your system volume, and that -you'll need a workaround to install Nix. - -The recommended approach, which creates an unencrypted APFS volume for -your Nix store and a "synthetic" empty directory to mount it over at -`/nix`, is least likely to impair Nix or your system. - -> **Note** -> -> With all separate-volume approaches, it's possible something on your -> system (particularly daemons/services and restored apps) may need -> access to your Nix store before the volume is mounted. Adding -> additional encryption makes this more likely. - -If you're using a recent Mac with a [T2 -chip](https://www.apple.com/euro/mac/shared/docs/Apple_T2_Security_Chip_Overview.pdf), -your drive will still be encrypted at rest (in which case "unencrypted" -is a bit of a misnomer). To use this approach, just install Nix with: - -```console -$ sh <(curl -L https://nixos.org/nix/install) --darwin-use-unencrypted-nix-store-volume -``` - -If you don't like the sound of this, you'll want to weigh the other -approaches and tradeoffs detailed in this section. - -> **Note** -> -> All of the known workarounds have drawbacks, but we hope better -> solutions will be available in the future. Some that we have our eye -> on are: -> -> 1. A true firmlink would enable the Nix store to live on the primary -> data volume without the build problems caused by the symlink -> approach. End users cannot currently create true firmlinks. -> -> 2. If the Nix store volume shared FileVault encryption with the -> primary data volume (probably by using the same volume group and -> role), FileVault encryption could be easily supported by the -> installer without requiring manual setup by each user. - -## Change the Nix store path prefix - -Changing the default prefix for the Nix store is a simple approach which -enables you to leave it on your root volume, where it can take full -advantage of FileVault encryption if enabled. Unfortunately, this -approach also opts your device out of some benefits that are enabled by -using the same prefix across systems: - - - Your system won't be able to take advantage of the binary cache - (unless someone is able to stand up and support duplicate caching - infrastructure), which means you'll spend more time waiting for - builds. - - - It's harder to build and deploy packages to Linux systems. - -It would also possible (and often requested) to just apply this change -ecosystem-wide, but it's an intrusive process that has side effects we -want to avoid for now. - -## Use a separate encrypted volume - -If you like, you can also add encryption to the recommended approach -taken by the installer. You can do this by pre-creating an encrypted -volume before you run the installer--or you can run the installer and -encrypt the volume it creates later. - -In either case, adding encryption to a second volume isn't quite as -simple as enabling FileVault for your boot volume. Before you dive in, -there are a few things to weigh: - -1. The additional volume won't be encrypted with your existing - FileVault key, so you'll need another mechanism to decrypt the - volume. - -2. You can store the password in Keychain to automatically decrypt the - volume on boot--but it'll have to wait on Keychain and may not mount - before your GUI apps restore. If any of your launchd agents or apps - depend on Nix-installed software (for example, if you use a - Nix-installed login shell), the restore may fail or break. - - On a case-by-case basis, you may be able to work around this problem - by using `wait4path` to block execution until your executable is - available. - - It's also possible to decrypt and mount the volume earlier with a - login hook--but this mechanism appears to be deprecated and its - future is unclear. - -3. You can hard-code the password in the clear, so that your store - volume can be decrypted before Keychain is available. - -If you are comfortable navigating these tradeoffs, you can encrypt the -volume with something along the lines of: - -```console -$ diskutil apfs enableFileVault /nix -user disk -``` - -## Symlink the Nix store to a custom location - -Another simple approach is using `/etc/synthetic.conf` to symlink the -Nix store to the data volume. This option also enables your store to -share any configured FileVault encryption. Unfortunately, builds that -resolve the symlink may leak the canonical path or even fail. - -Because of these downsides, we can't recommend this approach. - -## Notes on the recommended approach - -This section goes into a little more detail on the recommended approach. -You don't need to understand it to run the installer, but it can serve -as a helpful reference if you run into trouble. - -1. In order to compose user-writable locations into the new read-only - system root, Apple introduced a new concept called `firmlinks`, - which it describes as a "bi-directional wormhole" between two - filesystems. You can see the current firmlinks in - `/usr/share/firmlinks`. Unfortunately, firmlinks aren't (currently?) - user-configurable. - - For special cases like NFS mount points or package manager roots, - [synthetic.conf(5)](https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man5/synthetic.conf.5.html) - supports limited user-controlled file-creation (of symlinks, and - synthetic empty directories) at `/`. To create a synthetic empty - directory for mounting at `/nix`, add the following line to - `/etc/synthetic.conf` (create it if necessary): - - nix - -2. This configuration is applied at boot time, but you can use - `apfs.util` to trigger creation (not deletion) of new entries - without a reboot: - - ```console - $ /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B - ``` - -3. Create the new APFS volume with diskutil: - - ```console - $ sudo diskutil apfs addVolume diskX APFS 'Nix Store' -mountpoint /nix - ``` - -4. Using `vifs`, add the new mount to `/etc/fstab`. If it doesn't - already have other entries, it should look something like: - - # - # Warning - this file should only be modified with vifs(8) - # - # Failure to do so is unsupported and may be destructive. - # - LABEL=Nix\040Store /nix apfs rw,nobrowse - - The nobrowse setting will keep Spotlight from indexing this volume, - and keep it from showing up on your desktop. +# 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> +<!-- 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. + +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 +this to run the installer, but it may help if you run into trouble: + +- create a new APFS volume for your Nix store +- update `/etc/synthetic.conf` to direct macOS to create a "synthetic" + empty root directory to mount your volume +- specify mount options for the volume in `/etc/fstab` +- if you have FileVault enabled + - generate an encryption password + - put it in your system Keychain + - use it to encrypt the volume +- create a system LaunchDaemon to mount this volume early enough in the + boot process to avoid problems loading or restoring any programs that + need access to your Nix store # Installing a pinned Nix version from a URL diff --git a/doc/manual/src/installation/prerequisites-source.md b/doc/manual/src/installation/prerequisites-source.md index 12758c5e1..40cb79627 100644 --- a/doc/manual/src/installation/prerequisites-source.md +++ b/doc/manual/src/installation/prerequisites-source.md @@ -26,15 +26,6 @@ available for download from the official repository <https://github.com/google/brotli>. - - The bzip2 compressor program and the `libbz2` library. Thus you must - have bzip2 installed, including development headers and libraries. - If your distribution does not provide these, you can obtain bzip2 - from - <https://sourceware.org/bzip2/>. - - - `liblzma`, which is provided by XZ Utils. If your distribution does - not provide this, you can get it from <https://tukaani.org/xz/>. - - cURL and its library. If your distribution does not provide it, you can get it from <https://curl.haxx.se/>. @@ -69,6 +60,3 @@ `--disable-seccomp-sandboxing` option to the `configure` script (Not recommended unless your system doesn't support `libseccomp`). To get the library, visit <https://github.com/seccomp/libseccomp>. - - - Niels Lohmann's [JSON library](https://github.com/nlohmann/json). - diff --git a/doc/manual/src/package-management/s3-substituter.md b/doc/manual/src/package-management/s3-substituter.md index a4f4d561f..30f2b2e11 100644 --- a/doc/manual/src/package-management/s3-substituter.md +++ b/doc/manual/src/package-management/s3-substituter.md @@ -7,17 +7,17 @@ cache mechanism that Nix usually uses to fetch prebuilt binaries from The following options can be specified as URL parameters to the S3 URL: - - `profile` + - `profile`\ The name of the AWS configuration profile to use. By default Nix will use the `default` profile. - - `region` + - `region`\ The region of the S3 bucket. `us–east-1` by default. If your bucket is not in `us–east-1`, you should always explicitly specify the region parameter. - - `endpoint` + - `endpoint`\ The URL to your S3-compatible service, for when not using Amazon S3. Do not specify this value if you're using Amazon S3. @@ -26,7 +26,7 @@ The following options can be specified as URL parameters to the S3 URL: > This endpoint must support HTTPS and will use path-based > addressing instead of virtual host based addressing. - - `scheme` + - `scheme`\ The scheme used for S3 requests, `https` (default) or `http`. This option allows you to disable HTTPS for binary caches which don't support it. |