ghc panic

I got this error:

ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.2 for x86_64-unknown-mingw32):
        initTc: unsolved constraints
  WC {wc_insol = [W] %_a1El :: t_a1Ek[tau:1] (CHoleCan: %)}

while compiling the following code

halveEvens :: [Integer] -> [Integer]
halveEvens = map . filter (\c -> c%2 == 0)

Trac metadata

Trac field	Value
Version	8.0.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed weight to 5

added Tbug Trac import labels

closed

Works in HEAD and 8.2.1 RC. Thanks for the report!

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedDuplicate
Related	- → #13106 (closed)

added compiler crash label

added Pnormal label