Fwd: Haskell and guix

[David Craven]

Hi!

Can someone explain to me how to build a Haskell package? Or put
differently, why am I getting this error message?

Package has never been configured. Configuring with default flags. If this
fails, please run configure manually.
cabal: Use of GHC's environment variable GHC_PACKAGE_PATH is incompatible with
Cabal. Use the flag --package-db to specify a package database (it can be used
multiple times).

Steps to reproduce are:
guix environment idris --ad-hoc cabal-install
cabal build

Also if we have a Haskell expert here,

what is the difference between runhaskell Setup.hs test and cabal test?