Wrong Template Haskell desugaring

This code

{-# LANGUAGE TemplateHaskell, PolyKinds, TypeFamilies #-}

module T9160 where

$( [d| class C (a :: k) where
          type F (a :: k) :: *
    |]
 )

yields

T9160.hs:5:4:
    Kind variable also used as type variable: ‘k_a2cl’
    In the declaration for class C_a2cj

which is utterly bogus.

Trac metadata

Trac field	Value
Version	7.8.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture