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Diffstat (limited to 'doc/manual/src/command-ref/env-common.md')
| -rw-r--r-- | doc/manual/src/command-ref/env-common.md | 74 |
1 files changed, 39 insertions, 35 deletions
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 |