mirror of
https://github.com/NixOS/nix
synced 2024-10-18 00:16:11 -04:00
eb7d7780b1
This is needed to avoid this https://github.com/mesonbuild/meson/issues/13774 when we go back to making our subproject directory `src`.
78 lines
3.1 KiB
Markdown
78 lines
3.1 KiB
Markdown
# Name
|
|
|
|
`nix.conf` - Nix configuration file
|
|
|
|
# Description
|
|
|
|
Nix supports a variety of configuration settings, which are read from configuration files or taken as command line flags.
|
|
|
|
## Configuration file
|
|
|
|
By default Nix reads settings from the following places, in that order:
|
|
|
|
1. The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e. `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if [`NIX_CONF_DIR`](./env-common.md#env-NIX_CONF_DIR) is set.
|
|
|
|
Values loaded in this file are not forwarded to the Nix daemon.
|
|
The client assumes that the daemon has already loaded them.
|
|
|
|
1. If [`NIX_USER_CONF_FILES`](./env-common.md#env-NIX_USER_CONF_FILES) is set, then each path separated by `:` will be loaded in reverse order.
|
|
|
|
Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS` and [`XDG_CONFIG_HOME`](./env-common.md#env-XDG_CONFIG_HOME).
|
|
If unset, `XDG_CONFIG_DIRS` defaults to `/etc/xdg`, and `XDG_CONFIG_HOME` defaults to `$HOME/.config` as per [XDG Base Directory Specification](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).
|
|
|
|
1. If [`NIX_CONFIG`](./env-common.md#env-NIX_CONFIG) is set, its contents are treated as the contents of a configuration file.
|
|
|
|
### File format
|
|
|
|
Configuration files consist of `name = value` pairs, one per line.
|
|
Comments start with a `#` character.
|
|
|
|
Example:
|
|
|
|
```
|
|
keep-outputs = true # Nice for developers
|
|
keep-derivations = true # Idem
|
|
```
|
|
|
|
Other files can be included with a line like `include <path>`, where `<path>` is interpreted relative to the current configuration file.
|
|
A missing file is an error unless `!include` is used instead.
|
|
|
|
A configuration setting usually overrides any previous value.
|
|
However, for settings that take a list of items, you can prefix the name of the setting by `extra-` to *append* to the previous value.
|
|
|
|
For instance,
|
|
|
|
```
|
|
substituters = a b
|
|
extra-substituters = c d
|
|
```
|
|
|
|
defines the `substituters` setting to be `a b c d`.
|
|
|
|
Unknown option names are not an error, and are simply ignored with a warning.
|
|
|
|
## Command line flags
|
|
|
|
Configuration options can be set on the command line, overriding the values set in the [configuration file](#configuration-file):
|
|
|
|
- Every configuration setting has corresponding command line flag (e.g. `--max-jobs 16`).
|
|
Boolean settings do not need an argument, and can be explicitly disabled with the `no-` prefix (e.g. `--keep-failed` and `--no-keep-failed`).
|
|
|
|
Unknown option names are invalid flags (unless there is already a flag with that name), and are rejected with an error.
|
|
|
|
- The flag `--option <name> <value>` is interpreted exactly like a `<name> = <value>` in a setting file.
|
|
|
|
Unknown option names are ignored with a warning.
|
|
|
|
The `extra-` prefix is supported for settings that take a list of items (e.g. `--extra-trusted users alice` or `--option extra-trusted-users alice`).
|
|
|
|
## Integer settings
|
|
|
|
Settings that have an integer type support the suffixes `K`, `M`, `G`
|
|
and `T`. These cause the specified value to be multiplied by 2^10,
|
|
2^20, 2^30 and 2^40, respectively. For instance, `--min-free 1M` is
|
|
equivalent to `--min-free 1048576`.
|
|
|
|
# Available settings
|
|
|