GHC panics with forall and constraint

λ> type Maybeify c = forall d. (c d) => ((~) (Maybe d))

<interactive>:2:39: error:ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.1 for x86_64-apple-darwin):
	print_equality ~

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information

Admin message

GHC panics with forall and constraint