ghc: panic! (the 'impossible' happened)

• *Command**

ghc -c prettystub.hs

• *Result**

ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.2 for x86_64-unknown-mingw32):
        initTc: unsolved constraints
  WC {wc_insol =
        [W] hexEscape_a2yj :: t_a2yi[tau:1] (CHoleCan: hexEscape)}

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

Trac metadata

Trac field	Value
Version	8.0.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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