Options

The following options are allowed for all nix-env operations, but may not always have an effect.

• --file / -f path

  Specifies the Nix expression (designated below as the active Nix expression) used by the --install, --upgrade, and --query --available operations to obtain derivations. The default is ~/.nix-defexpr.

  If the argument 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 include a single top-level directory containing at least a file named default.nix.

• --profile / -p path

  Specifies the profile to be used by those operations that operate on a profile (designated below as the active profile). A profile is a sequence of user environments called generations, one of which is the current generation.

• --dry-run

  For the --install, --upgrade, --uninstall, --switch-generation, --delete-generations and --rollback operations, this flag will cause nix-env to print what would be done if this flag had not been specified, without actually doing it.

  --dry-run also prints out which paths will be substituted (i.e., downloaded) and which paths will be built from source (because no substitute is available).

• --system-filter system

  By default, operations such as --query --available show derivations matching any platform. This option allows you to use derivations for the specified platform system.