[Nix-dev] Help with ghc errors after nix-channel --update

[Peter Simons]

Hi Benno,

 > I just assumed that since I had two versions of hashable with
 > different cabal hashes installed, that one of them was a GHC core
 > package.

oh, that doesn't sound good. There should be only one version of
hashable active per compiler version, really.


 > 1. Install a package depending on hashable.
 > 2. Update nixpkgs. The new nixpkgs contains a hashable with a different
 >    cabal hash because hydra rebuilt hashable.
 > 3. Now install another package depending on hashable. I now have two
 >    incompatible hashable versions.

Have you tried running "nix-env -u \* --always" to update the package
from (1) to the new hashable version?

Best regards,
Peter