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Typed Template Haskell splices broken in HEAD (7.11)

In the latest HEAD (e2b579e8) when I say:

$$(return [
   SigD (mkName "m")
        (ForallT [PlainTV (mkName "a")]
                 []
                 (AppT (AppT ArrowT (VarT (mkName "a"))) (VarT (mkName "a"))))
 , FunD (mkName "m")
        [Clause [VarP (mkName "x")] (NormalB (VarE (mkName "x"))) []]
 ])

I get:

ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 7.11.20151007 for x86_64-unknown-linux):
        runRnSplice
  $$(return
       [SigD
          (mkName "m")
          (ForallT
             [PlainTV (mkName "a")]
             []
             (AppT (AppT ArrowT (VarT (mkName "a"))) (VarT (mkName "a")))),
        FunD
          (mkName "m")
          [Clause [VarP (mkName "x")] (NormalB (VarE (mkName "x"))) []]])

This code compiles correctly in GHC 7.10.1.

Trac metadata
Trac field Value
Version 7.11
Type Bug
TypeOfFailure OtherFailure
Priority high
Resolution Unresolved
Component Template Haskell
Test case
Differential revisions
BlockedBy
Related
Blocking
CC goldfire
Operating system
Architecture
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