[GHC] #7022: Kind variable scoping problem in Iface file when using Template Haskell

[GHC]

#7022: Kind variable scoping problem in Iface file when using Template Haskell
-------------------------------+--------------------------------------------
  Reporter:  goldfire          |          Owner:                           
      Type:  bug               |         Status:  new                      
  Priority:  normal            |      Milestone:                           
 Component:  Compiler          |        Version:  7.5                      
Resolution:                    |       Keywords:  TemplateHaskell PolyKinds
        Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple         
   Failure:  None/Unknown      |     Difficulty:  Unknown                  
  Testcase:  polykinds/T7022   |      Blockedby:                           
  Blocking:                    |        Related:                           
-------------------------------+--------------------------------------------

Comment(by simonpj):

 Aha.  I don't have time to validate, but I bet this fixes it:
 {{{
 diff --git a/compiler/iface/MkIface.lhs b/compiler/iface/MkIface.lhs
 index ce07b37..18dd8f4 100644
 --- a/compiler/iface/MkIface.lhs
 +++ b/compiler/iface/MkIface.lhs
 @@ -1498,8 +1498,8 @@ tyConToIfaceDecl env tycon

      (syn_rhs, syn_ki)
         = case synTyConRhs tycon of
 -            SynFamilyTyCon  -> (Nothing,               tidyToIfaceType
 env1 (synTyConResKind tycon))
 -            SynonymTyCon ty -> (Just (toIfaceType ty), tidyToIfaceType
 env1 (typeKind ty))
 +            SynFamilyTyCon  -> (Nothing,
 tidyToIfaceType env1 (synTyConResKind tycon))
 +            SynonymTyCon ty -> (Just (tidyToIfaceType env1 ty),
 tidyToIfaceType env1 (typeKind ty))

      ifaceConDecls (NewTyCon { data_con = con })     = IfNewTyCon
 (ifaceConDecl con)
 }}}
 Can you test, validate, and commit if so?  It's just a typo in my previous
 fix.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7022#comment:6>
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