[Haskell-cafe] package show needs QuickCheck<2.6?

[Johannes Waldmann]

Hi, I noticed that compilation of mueval (recent: 0.8.2) breaks 
because show (0.5) cannot be built: 
it seems the type of Failure changed in QuickCheck (from 2.5 to 2.6).
The build succeeds with --constraint 'QuickCheck<2.6' .