Merge remote-tracking branch 'upstream/master' into path-info

5 files changed, 48 insertions, 28 deletions

diff --git a/doc/manual/src/command-ref/conf-file-prefix.md b/doc/manual/src/command-ref/conf-file-prefix.md
index 3140170ab..44b7ba86d 100644
--- a/doc/manual/src/command-ref/conf-file-prefix.md
+++ b/doc/manual/src/command-ref/conf-file-prefix.md
@@ -16,8 +16,9 @@ By default Nix reads settings from the following places:
     will be loaded in reverse order.
 
     Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS`
-    and `XDG_CONFIG_HOME`. If these are unset, it will look in
-    `$HOME/.config/nix.conf`.
+    and `XDG_CONFIG_HOME`. If unset, `XDG_CONFIG_DIRS` defaults to
+    `/etc/xdg`, and `XDG_CONFIG_HOME` defaults to `$HOME/.config`
+    as per [XDG Base Directory Specification](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).
 
   - If `NIX_CONFIG` is set, its contents is treated as the contents of
     a configuration file.
diff --git a/doc/manual/src/command-ref/nix-env.md b/doc/manual/src/command-ref/nix-env.md
index 9138fa05a..8d6abaf52 100644
--- a/doc/manual/src/command-ref/nix-env.md
+++ b/doc/manual/src/command-ref/nix-env.md
@@ -238,7 +238,16 @@ a number of possible ways:
 
 ## Examples
 
-To install a specific version of `gcc` from the active Nix expression:
+To install a package using a specific attribute path from the active Nix expression:
+
+```console
+$ nix-env -iA gcc40mips
+installing `gcc-4.0.2'
+$ nix-env -iA xorg.xorgserver
+installing `xorg-server-1.2.0'
+```
+
+To install a specific version of `gcc` using the derivation name:
 
 ```console
 $ nix-env --install gcc-3.3.2
@@ -246,6 +255,9 @@ installing `gcc-3.3.2'
 uninstalling `gcc-3.1'
 ```
 
+Using attribute path for selecting a package is preferred,
+as it is much faster and there will not be multiple matches.
+
 Note the previously installed version is removed, since
 `--preserve-installed` was not specified.
 
@@ -256,13 +268,6 @@ $ nix-env --install gcc
 installing `gcc-3.3.2'
 ```
 
-To install using a specific attribute:
-
-```console
-$ nix-env -i -A gcc40mips
-$ nix-env -i -A xorg.xorgserver
-```
-
 To install all derivations in the Nix expression `foo.nix`:
 
 ```console
@@ -374,22 +379,29 @@ For the other flags, see `--install`.
 ## Examples
 
 ```console
-$ nix-env --upgrade gcc
+$ nix-env --upgrade -A nixpkgs.gcc
 upgrading `gcc-3.3.1' to `gcc-3.4'
 ```
 
+When there are no updates available, nothing will happen:
+
 ```console
-$ nix-env -u gcc-3.3.2 --always (switch to a specific version)
-upgrading `gcc-3.4' to `gcc-3.3.2'
+$ nix-env --upgrade -A nixpkgs.pan
 ```
 
+Using `-A` is preferred when possible, as it is faster and unambiguous but
+it is also possible to upgrade to a specific version by matching the derivation name:
+
 ```console
-$ nix-env --upgrade pan
-(no upgrades available, so nothing happens)
+$ nix-env -u gcc-3.3.2 --always
+upgrading `gcc-3.4' to `gcc-3.3.2'
 ```
 
+To try to upgrade everything
+(matching packages based on the part of the derivation name without version):
+
 ```console
-$ nix-env -u (try to upgrade everything)
+$ nix-env -u
 upgrading `hello-2.1.2' to `hello-2.1.3'
 upgrading `mozilla-1.2' to `mozilla-1.4'
 ```
@@ -401,7 +413,7 @@ 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`
-if their package names match, and the version of `y` is higher that that
+if their package names match, and the version of `y` is higher than that
 of `x`.
 
 The versions are compared by splitting them into contiguous components
diff --git a/doc/manual/src/command-ref/nix-shell.md b/doc/manual/src/command-ref/nix-shell.md
index 72f6730f1..a2b6d8a8e 100644
--- a/doc/manual/src/command-ref/nix-shell.md
+++ b/doc/manual/src/command-ref/nix-shell.md
@@ -11,8 +11,8 @@
   [`--command` *cmd*]
   [`--run` *cmd*]
   [`--exclude` *regexp*]
-  [--pure]
-  [--keep *name*]
+  [`--pure`]
+  [`--keep` *name*]
   {{`--packages` | `-p`} {*packages* | *expressions*} … | [*path*]}
 
 # Description
@@ -101,7 +101,8 @@ The following common options are supported:
 
   - `NIX_BUILD_SHELL`\
     Shell used to start the interactive environment. Defaults to the
-    `bash` found in `PATH`.
+    `bash` found in `<nixpkgs>`, falling back to the `bash` found in
+    `PATH` if not found.
 
 # Examples
 
@@ -110,13 +111,19 @@ shell in which to build it:
 
 ```console
 $ nix-shell '<nixpkgs>' -A pan
-[nix-shell]$ unpackPhase
+[nix-shell]$ eval ${unpackPhase:-unpackPhase}
 [nix-shell]$ cd pan-*
-[nix-shell]$ configurePhase
-[nix-shell]$ buildPhase
+[nix-shell]$ eval ${configurePhase:-configurePhase}
+[nix-shell]$ eval ${buildPhase:-buildPhase}
 [nix-shell]$ ./pan/gui/pan
 ```
 
+The reason we use form `eval ${configurePhase:-configurePhase}` here is because
+those packages that override these phases do so by exporting the overridden
+values in the environment variable of the same name.
+Here bash is being told to either evaluate the contents of 'configurePhase',
+if it exists as a variable, otherwise evaluate the configurePhase function.
+
 To clear the environment first, and do some additional automatic
 initialisation of the interactive shell:
 
diff --git a/doc/manual/src/command-ref/nix-store.md b/doc/manual/src/command-ref/nix-store.md
index 7a131dc02..7db9f0c1c 100644
--- a/doc/manual/src/command-ref/nix-store.md
+++ b/doc/manual/src/command-ref/nix-store.md
@@ -125,7 +125,7 @@ Special exit codes:
 
   - `104`\
     Not deterministic, the build succeeded in check mode but the
-    resulting output is not binary reproducable.
+    resulting output is not binary reproducible.
 
 With the `--keep-going` flag it's possible for multiple failures to
 occur, in this case the 1xx status codes are or combined using binary
@@ -321,8 +321,8 @@ symlink.
     This query has one option:
 
       - `--include-outputs`
-        Also include the output path of store derivations, and their
-        closures.
+        Also include the existing output paths of store derivations,
+        and their closures.
 
     This query can be used to implement various kinds of deployment. A
     *source deployment* is obtained by distributing the closure of a
diff --git a/doc/manual/src/command-ref/opt-common.md b/doc/manual/src/command-ref/opt-common.md
index 47862bc09..7ee1a26bc 100644
--- a/doc/manual/src/command-ref/opt-common.md
+++ b/doc/manual/src/command-ref/opt-common.md
@@ -162,11 +162,11 @@ Most Nix commands accept the following command-line options:
     }: ...
     ```
 
-    So if you call this Nix expression (e.g., when you do `nix-env -i
+    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
     the `system` argument. You can override this using `--arg`, e.g.,
-    `nix-env -i pkgname --arg system \"i686-freebsd\"`. (Note that
+    `nix-env -iA pkgname --arg system \"i686-freebsd\"`. (Note that
     since the argument is a Nix string literal, you have to escape the
     quotes.)