I see. I tried to report this as a bug, fwiw: https://bitbucket.org/xnyhps/haskell-unittyped/issue/3/num-instance-isnt-imported https://bitbucket.org/xnyhps/ha

I see. I tried to report this as a bug, fwiw: https://bitbucket.org/xnyhps/haskell-unittyped/issue/3/num-instance-isnt-imported https://bitbucket.org/xnyhps/haskell-unittyped/issue/3/num-i... Btw, it's weird... I just tried ack-grep "Num\b" and I cannot see any instance of Num defined anywhere inside unittyped's src PS: ok, since I wanted to see exactly what was the problem with unittyped compiling under ghc7.8 I cloned the sources, but I forgot to checkout the actual release... thus running directly from tip was the cause Installing it directly from hackage solved it, it's embarrassing how I was stunned by this in hindsight