name: temp-dir internalName: tempDir settingType: PathsSetting<std::optional> default: null

The directory on the host used as the default temporary directory.

If not set, Nix will use the system temporary directory indicated by the TMPDIR environment variable.

This will be used for anything that would otherwise fall back to TMPDIR, and the inherited TMPDIR value will be preserved for child processes to use. If build-dir is set, that takes precedence over this where it applies.

If set, the value must be a path that exists and is accessible to all users.