[GHC] #7176: Failure to let kind variable remain uninstantiated when not needed

[GHC]

#7176: Failure to let kind variable remain uninstantiated when not needed
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    Reporter:  goldfire                |       Owner:                  
        Type:  bug                     |      Status:  new             
    Priority:  normal                  |   Milestone:                  
   Component:  Compiler                |     Version:  7.6.1-rc1       
    Keywords:  PolyKinds TypeFamilies  |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple        |     Failure:  None/Unknown    
  Difficulty:  Unknown                 |    Testcase:                  
   Blockedby:                          |    Blocking:                  
     Related:                          |  
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Changes (by simonpj):

  * difficulty:  => Unknown


Comment:

 Aha. I have fixed this on the 7.6 branch thus:
 {{{
 commit 5133bb97a47340a9008615e412fcf62f7762bea8
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Wed Aug 22 18:01:57 2012 +0100

     Allocate a fresh META unique in newMetaKindVar

     Fixes Trac #7176 on the branch.  HEAD has a better fix
     (the big patch to untouchable handling)

  compiler/typecheck/TcMType.lhs |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
 }}}
 Separate fix for HEAD coming

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7176#comment:1>
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