GHC Panic (The Impossible Happened)

Error message:

ghc: panic! (the 'impossible' happened)
  (GHC version 7.4.1 for x86_64-unknown-linux):
	compiler/rename/RnPat.lhs:535:39-79: Irrefutable pattern failed for pattern gres@(gre : _)

Cause:

Importing a Module containing a record-syntax defined datatype, hiding one of the record fields, causes the use of the language pragma RecordWildCards to make GHC encounter a fatal error. A minimal reproduction case is attached to this ticket.

Trac metadata

Trac field	Value
Version	7.4.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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GHC Panic (The Impossible Happened)