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-rw-r--r--doc/manual/src/command-ref/env-common.md73
1 files changed, 21 insertions, 52 deletions
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