diff options
Diffstat (limited to 'doc/manual/src/command-ref/env-common.md')
| -rw-r--r-- | doc/manual/src/command-ref/env-common.md | 68 |
1 files changed, 43 insertions, 25 deletions
diff --git a/doc/manual/src/command-ref/env-common.md b/doc/manual/src/command-ref/env-common.md index c5d38db47..b4a9bb2a9 100644 --- a/doc/manual/src/command-ref/env-common.md +++ b/doc/manual/src/command-ref/env-common.md @@ -2,18 +2,29 @@ Most Nix commands interpret the following environment variables: - - [`IN_NIX_SHELL`]{#env-IN_NIX_SHELL}\ + - <span id="env-IN_NIX_SHELL">[`IN_NIX_SHELL`](#env-IN_NIX_SHELL)</span>\ Indicator that tells if the current environment was set up by `nix-shell`. It can have the values `pure` or `impure`. - - [`NIX_PATH`]{#env-NIX_PATH}\ + - <span id="env-NIX_PATH">[`NIX_PATH`](#env-NIX_PATH)</span>\ A colon-separated list of directories used to look up the location of Nix - expressions using [paths](../language/values.md#type-path) + expressions using [paths](@docroot@/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.md#opt-I). + [`-I` option](@docroot@/command-ref/opt-common.md#opt-I). - - [`NIX_IGNORE_SYMLINK_STORE`]{#env-NIX_IGNORE_SYMLINK_STORE}\ + If `NIX_PATH` is not set at all, Nix will fall back to the following list in [impure](@docroot@/command-ref/conf-file.md#conf-pure-eval) and [unrestricted](@docroot@/command-ref/conf-file.md#conf-restrict-eval) evaluation mode: + + 1. `$HOME/.nix-defexpr/channels` + 2. `nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixpkgs` + 3. `/nix/var/nix/profiles/per-user/root/channels` + + If `NIX_PATH` is set to an empty string, resolving search paths will always fail. + For example, attempting to use `<nixpkgs>` will produce: + + error: file 'nixpkgs' was not found in the Nix search path + + - <span id="env-NIX_IGNORE_SYMLINK_STORE">[`NIX_IGNORE_SYMLINK_STORE`](#env-NIX_IGNORE_SYMLINK_STORE)</span>\ 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 @@ -35,72 +46,79 @@ Most Nix commands interpret the following environment variables: Consult the mount 8 manual page for details. - - [`NIX_STORE_DIR`]{#env-NIX_STORE_DIR}\ + - <span id="env-NIX_STORE_DIR">[`NIX_STORE_DIR`](#env-NIX_STORE_DIR)</span>\ Overrides the location of the Nix store (default `prefix/store`). - - [`NIX_DATA_DIR`]{#env-NIX_DATA_DIR}\ + - <span id="env-NIX_DATA_DIR">[`NIX_DATA_DIR`](#env-NIX_DATA_DIR)</span>\ Overrides the location of the Nix static data directory (default `prefix/share`). - - [`NIX_LOG_DIR`]{#env-NIX_LOG_DIR}\ + - <span id="env-NIX_LOG_DIR">[`NIX_LOG_DIR`](#env-NIX_LOG_DIR)</span>\ Overrides the location of the Nix log directory (default `prefix/var/log/nix`). - - [`NIX_STATE_DIR`]{#env-NIX_STATE_DIR}\ + - <span id="env-NIX_STATE_DIR">[`NIX_STATE_DIR`](#env-NIX_STATE_DIR)</span>\ Overrides the location of the Nix state directory (default `prefix/var/nix`). - - [`NIX_CONF_DIR`]{#env-NIX_CONF_DIR}\ + - <span id="env-NIX_CONF_DIR">[`NIX_CONF_DIR`](#env-NIX_CONF_DIR)</span>\ Overrides the location of the system Nix configuration directory (default `prefix/etc/nix`). - - [`NIX_CONFIG`]{#env-NIX_CONFIG}\ + - <span id="env-NIX_CONFIG">[`NIX_CONFIG`](#env-NIX_CONFIG)</span>\ 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`]{#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. + - <span id="env-NIX_USER_CONF_FILES">[`NIX_USER_CONF_FILES`](#env-NIX_USER_CONF_FILES)</span>\ + Overrides the location of the Nix user configuration files to load from. - - [`TMPDIR`]{#env-TMPDIR}\ + The default are the locations according to the [XDG Base Directory Specification]. + See the [XDG Base Directories](#xdg-base-directories) sub-section for details. + + The variable is treated as a list separated by the `:` token. + + - <span id="env-TMPDIR">[`TMPDIR`](#env-TMPDIR)</span>\ 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`]{#env-NIX_REMOTE}\ + - <span id="env-NIX_REMOTE">[`NIX_REMOTE`](#env-NIX_REMOTE)</span>\ 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 + Nix installations](@docroot@/installation/multi-user.md). If the Nix daemon's Unix socket is at some non-standard path, this variable should be set to `unix://path/to/socket`. Otherwise, it should be left unset. - - [`NIX_SHOW_STATS`]{#env-NIX_SHOW_STATS}\ + - <span id="env-NIX_SHOW_STATS">[`NIX_SHOW_STATS`](#env-NIX_SHOW_STATS)</span>\ If set to `1`, Nix will print some evaluation statistics, such as the number of values allocated. - - [`NIX_COUNT_CALLS`]{#env-NIX_COUNT_CALLS}\ + - <span id="env-NIX_COUNT_CALLS">[`NIX_COUNT_CALLS`](#env-NIX_COUNT_CALLS)</span>\ 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`]{#env-GC_INITIAL_HEAP_SIZE}\ + - <span id="env-GC_INITIAL_HEAP_SIZE">[`GC_INITIAL_HEAP_SIZE`](#env-GC_INITIAL_HEAP_SIZE)</span>\ 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 will increase runtime due to the overhead of garbage collection. -## XDG Base Directory +## XDG Base Directories + +Nix follows the [XDG Base Directory Specification]. + +For backwards compatibility, Nix commands will follow the standard only when [`use-xdg-base-directories`] is enabled. +[New Nix commands](@docroot@/command-ref/new-cli/nix.md) (experimental) conform to the standard by default. -New Nix commands conform to the [XDG Base Directory Specification], and use the following environment variables to determine locations of various state and configuration files: +The following environment variables are used to determine locations of various state and configuration files: - [`XDG_CONFIG_HOME`]{#env-XDG_CONFIG_HOME} (default `~/.config`) - [`XDG_STATE_HOME`]{#env-XDG_STATE_HOME} (default `~/.local/state`) - [`XDG_CACHE_HOME`]{#env-XDG_CACHE_HOME} (default `~/.cache`) -Classic Nix commands can also be made to follow this standard using the [`use-xdg-base-directories`] configuration option. [XDG Base Directory Specification]: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html -[`use-xdg-base-directories`]: ../command-ref/conf-file.md#conf-use-xdg-base-directories
\ No newline at end of file +[`use-xdg-base-directories`]: @docroot@/command-ref/conf-file.md#conf-use-xdg-base-directories |