@ljli, thanks for your PR! By analyzing the history of the files in this pull request, we identified @bennofs, @mdorman and @vcunat to be potential reviewers.

These changes should be in configuration-common, not configuration-nix

That's where I had them initially, but this is really a nix failure, the cabal files clearly state that 0.6.0.0 of all the packages are needed. But I guess that applies to many of the overrides in configuration-common and above. Updated incoming.

That is a good point. In general though, configuration-nix is really for things like native dependencies that aren't found without help etc and not for changing how the set of haskell packages is composed.

I wonder if cabal2nix / hackage2nix could do a better job here though. I will investigate this later. It feels hard though, as the whole package set must be coherent so hackage2nix cannot just let a single binary use a different version. It could do it for executables though, but then it would have to generate an overrideScope for executables which sounds hard.

Anyway, thanks very much for the PR!