Incorrect reported pattern synonym signature
data T where MkT :: (Show b) => b -> T --pattern ExNumPat :: () => Show b => b -> T pattern ExNumPat x = MkT x
GHC reports that
ExNumPat is missing a signature (correctly) but it reports the wrong type. The correct type is the one commented out.
pstest.hs:12:1: warning: Top-level binding with no type signature: ExNumPat :: forall b. Show b => b -> T