Sometimes proprietary software can only be redistributed unmodified. Make sure the builder doesn’t actually modify the original binaries; otherwise we’re breaking the license. For instance, the NVIDIA X11 drivers can be redistributed unmodified, but our builder applies `patchelf` to make them work. Thus, its license is `"unfree"` and it cannot be included in the Nixpkgs channel.

### `lib.licenses.unfree`, `"unfree"` {#lib.licenses.unfree-unfree}

Unfree package that cannot be redistributed. You can build it yourself, but you cannot redistribute the output of the derivation. Thus it cannot be included in the Nixpkgs channel.

### `lib.licenses.unfreeRedistributableFirmware`, `"unfree-redistributable-firmware"` {#lib.licenses.unfreeredistributablefirmware-unfree-redistributable-firmware}

This package supplies unfree, redistributable firmware. This is a separate value from `unfree-redistributable` because not everybody cares whether firmware is free.

## Source provenance {#sec-meta-sourceProvenance}

The value of a package's `meta.sourceProvenance` attribute specifies the provenance of the package's derivation outputs.

If a package contains elements that are not built from the original source by a nixpkgs derivation, the `meta.sourceProvenance` attribute should be a list containing one or more value from `lib.sourceTypes` defined in [`nixpkgs/lib/source-types.nix`](https://github.com/NixOS/nixpkgs/blob/master/lib/source-types.nix).

Adding this information helps users who have needs related to build transparency and supply-chain security to gain some visibility into their installed software or set policy to allow or disallow installation based on source provenance.

The presence of a particular `sourceType` in a package's `meta.sourceProvenance` list indicates that the package contains some components falling into that category, though the *absence* of that `sourceType` does not *guarantee* the absence of that category of `sourceType` in the package's contents. A package with no `meta.sourceProvenance` set implies it has no *known* `sourceType`s other than `fromSource`.

The meaning of the `meta.sourceProvenance` attribute does not depend on the value of the `meta.license` attribute.

### `lib.sourceTypes.fromSource` {#lib.sourceTypes.fromSource}

Package elements which are produced by a nixpkgs derivation which builds them from source code.

### `lib.sourceTypes.binaryNativeCode` {#lib.sourceTypes.binaryNativeCode}

Native code to be executed on the target system's CPU, built by a third party. This includes packages which wrap a downloaded AppImage or Debian package.

### `lib.sourceTypes.binaryFirmware` {#lib.sourceTypes.binaryFirmware}

Code to be executed on a peripheral device or embedded controller, built by a third party.

### `lib.sourceTypes.binaryBytecode` {#lib.sourceTypes.binaryBytecode}

Code to run on a VM interpreter or JIT compiled into bytecode by a third party. This includes packages which download Java `.jar` files from another source.