flox build import nixpkgs

NAME

flox-build-import-nixpkgs - Import package definition from nixpkgs

SYNOPSIS

flox [<general-options>] build import-nixpkgs
     [-d=<path>]
     [--force]
     [--stability <stability>]
     <installable>

DESCRIPTION

Import a package definition from nixpkgs for use in the environment. This command copies the source code of a package from nixpkgs into the environment's .flox/pkgs/ directory, allowing you to modify and build the package locally.

The package definition is imported as a Nix expression file at .flox/pkgs/<package>/default.nix, where <package> is the attribute path of the package (e.g., hello for nixpkgs#hello).

This is useful when you need to:

• Modify a package's build process
• Apply patches or customizations
• Debug package issues
• Create variants of existing packages

Installable format

The <installable> parameter can be specified in one of the following formats:

1. Attribute path only: hello (defaults to nixpkgs#hello)
2. Flake reference with attribute: nixpkgs#hello
3. Full flake reference: github:nixos/nixpkgs#hello

When using --stability, the installable must be a bare attribute path or the nixpkgs# prefix form. An explicit flake reference (e.g. github:nixos/nixpkgs#hello) cannot be combined with the flag.

OPTIONS

<installable> The package to import from nixpkgs. Can be specified as an attribute path (e.g., hello) or as a flake reference with attribute path (e.g., nixpkgs#hello).

--force Overwrite existing package file if it already exists. Without this flag, the command will fail if the package file already exists in the environment.

--stability <stability> Import using a base package set of the given stability as tracked by the catalog server. A stability (e.g., "stable" or "unstable") identifies a curated nixpkgs revision managed by the catalog server. When omitted, the default nixpkgs channel is used. Cannot be combined with an explicit flake reference in <installable>.

Environment Options

If no environment is specified for an environment command, the environment in the current directory or the active environment that was last activated is used.

-d, --dir Path containing a .flox/ directory.

General Options

-h, --help Prints help information.

The following options can be passed when running any flox subcommand but must be specified before the subcommand.

-v, --verbose Increase logging verbosity. Invoke multiple times for increasing detail.

-q, --quiet Silence logs except for errors.

EXAMPLES

Import a simple package

Import the hello package from nixpkgs:

flox build import-nixpkgs hello

This creates .flox/pkgs/hello/default.nix with the package definition.

Import using a specific stability

Import samba from the unstable channel as tracked by the catalog:

flox build import-nixpkgs samba --stability unstable

Import from a specific nixpkgs revision

Import a package from a specific nixpkgs revision:

flox build import-nixpkgs github:nixos/nixpkgs/nixos-23.11#hello

Overwrite an existing package

Force import a package, overwriting any existing definition:

flox build import-nixpkgs --force hello

Import a complex package

Import a package with a nested attribute path:

flox build import-nixpkgs python310Packages.requests

This creates .flox/pkgs/python310Packages/requests/default.nix.

NOTES

• This command only works with local environments (not managed or remote environments)
• The imported package definition is a snapshot of the source code at the time of import
• You can modify the imported package definition and build it using flox build
• The package will be available in the environment's build context

SEE ALSO

flox-build(1), flox-build-clean(1), manifest.toml(5)