# Revision history for distribution-nixpkgs
## 1.6.0
* `Distribution.Nixpkgs.PackageMap`
* `readNixpkgPackageMap`: instead of a list of arguments to pass to
`nix-env`, take path to nixpkgs and an optional nix expression
to pass to it as arguments.
* `readNixpkgPackageMap`: populate `PackageMap` with *all* attribute
paths that point to derivations instead of just one per derivation.
This fixes `resolve` not finding certain identifiers if there were
two attributes pointing to the same derivation in nixpkgs. See also
[#9](https://github.com/NixOS/distribution-nixpkgs/issues/9).