The attached versions.scm has been generated using `guix import hackage versions` and specifying that I want to build it with `#:haskell ,ghc-8.8`. Upon building, I get the error posted here: http://paste.debian.net/1203119/

I'm not entirely sure what the problem is, but it seems like when another version of ghc has been specified, dependencies built with another version of ghc no longer work.