GHC panics in incomplete program

I misspell a variable and GHC panics.

I have the following test1.hs file:

foo :: Double -> Double -> Bool
foo a b = c > b                                              

Then I do ghc -c test1.hs and get:

ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.2 for x86_64-unknown-linux):
	initTc: unsolved constraints
  WC {wc_insol = [W] x_a1LD :: t_a1LC[tau:1] (CHoleCan: x)}

If I add a "main" method to my test.hs, I get the expected

test1.hs:2:11: error: Variable not in scope: c :: Double

Trac metadata

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