[GHC] #12785: GHC panic, TypeFamily in equality constraint

[GHC]

#12785: GHC panic, TypeFamily in equality constraint
-------------------------------------+-------------------------------------
        Reporter:  heisenbug         |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by heisenbug):

 Hmmm, looks like a case is not implemented.

 in `tcTyVarDetails` this constructor should be checked:


 {{{#!haskell
 Id {
         varName    :: !Name,
         realUnique :: {-# UNPACK #-} !Int,
         varType    :: Type,
         idScope    :: IdScope,
         id_details :: IdDetails,        -- Stable, doesn't change
         id_info    :: IdInfo }          -- Unstable, updated by simplifier

 }}}

 '''Note:''' `setTcTyVarDetails` also looks like it is not total.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12785#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler