Hi John, Thank you, after installing gcc-toolchain, it worked! Then this is indeed a bug that should be very simple to fix? Just require gcc-toolchain (or some of its required features) as a GHC's dependency? I am also curious, what kind of testing (if any?) does Guix perform for packages?? Or is GHC already marked as broken? (Apology for repeated question marks :-)) ~/co/haskell-tiny-intro/exercise (master *)$ guix install gcc- toolchain...~/co/haskell-tiny-intro/exercise (master *)$ ghc a.hs[1 of 1] Compiling Main ( a.hs, a.o )Linking a ...~/co/haskell- tiny-intro/exercise (master *)$ ghc --versionThe Glorious Glasgow Haskell Compilation System, version 8.8.3 Cheers, Yasu On Sun, 2021-01-10 at 21:49 -0800, John Soo wrote: > Hi yasu, > Compiling with ghc requires a c toolchain (like gcc-toolchain) > installed to work. Can you try again after installing gcc-toolchain? > Ghc has not been perfect for me recently but I use it quite a lot. > > Hope that helps, > > John