Exception when encountering instance declarations without class name

Code

instance Bounded b => (a -> b) where
 minBound = const minBound
 maxBound = const maxBound

GHC 7.4.1 "crashes" with an exception if the class name is missing.

*** Exception: compiler/rename/RnSource.lhs:429:14-81: Irrefutable pattern failed for pattern Data.Maybe.Just (inst_tyvars,
                                                        _,
                                                        SrcLoc.L _ cls,
                                                        _)

Trac metadata

Trac field	Value
Version	7.4.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (Parser)
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