On Apr 10, 2014 3:33 AM, "Adam Bergmark" <adam@bergmark.nl> wrote:
>
> I agree with Erik that non-upgradeable packages should be constrained to installed in Cabal. I have this in my cabal config as well. Better error messages for this would be gravy.

Now fixed in Cabal HEAD. Base and ghc-prim already had an installed constraint, but we added template-haskell and integer-gmp/simple.