NixOS/nixpkgs — pull request #4869 by abbradar (2014-11-07 11:30:47+00:00)
Title: release-lib: add option to use another package set

This allows one to use release-lib for his own package trees, like this (release.nix for Hydra):
```
{ supportedSystems ? [ "x86_64-linux" ] }:
let
lib = import {
inherit supportedSystems;
packageSet = import ;
};
in
lib.mapTestOn (lib.packagesWithMetaPlatform lib.pkgs)
```