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ghc: panic! (the 'impossible' happened)

I got this message when trying to compile. It appears to be reproducible. Also I realize this is an outdate version of GHC so I'm going to update and see if it fixes itself.

(GHC version 7.4.1 for x86_64-unknown-linux):

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
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture
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