[GHC] #2714: No match in record selector Var.tcTyVarDetails

[GHC]

#2714: No match in record selector Var.tcTyVarDetails
-----------------------------------------------------+----------------------
    Reporter:  morrow                                |        Owner:                  
        Type:  bug                                   |       Status:  new             
    Priority:  normal                                |    Milestone:                  
   Component:  Compiler (Type checker)               |      Version:  6.10.1          
    Severity:  normal                                |   Resolution:                  
    Keywords:  Var, tcTyVarDetails, record selector  |     Testcase:                  
Architecture:  Unknown/Multiple                      |           Os:  Unknown/Multiple
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Comment (by morrow):

 Judging from the comment, this may have
 something to do with it? From TcUnify:

 {{{
 unBox :: BoxyType -> TcM TcType
 -- ...
 unBox (TyVarTy tv)
   | isTcTyVar tv                                -- It's a boxy type
 variable
   , MetaTv BoxTv ref <- tcTyVarDetails tv       -- NB: non-TcTyVars are
 possible
   = do  { cts <- readMutVar ref                 --     under nested
 quantifiers
 -- ...
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2714#comment:1>
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