[GHC] #8553: ASSERT failed compiler/typecheck/TcMType.lhs line 809

[GHC]

#8553: ASSERT failed compiler/typecheck/TcMType.lhs line 809
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        Reporter:  nomeata                  |            Owner:
            Type:  bug                      |           Status:  new
        Priority:  normal                   |        Milestone:
       Component:  Compiler (Type checker)  |          Version:  7.7
      Resolution:                           |         Keywords:
Operating System:  Unknown/Multiple         |     Architecture:
 Type of failure:  Compile-time crash       |  Unknown/Multiple
       Test Case:  gadt6 T7474 T5246        |       Difficulty:  Unknown
        Blocking:                           |       Blocked By:
                                            |  Related Tickets:
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"985663ea47487a9e567814ba000e81d65358bf02/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="985663ea47487a9e567814ba000e81d65358bf02"
 Fix type-equality in the type checker (fixes Trac #8553)

 For horrible reasons (Note [Comparison with OpenTypeKind] in Type), the
 function Type.eqType currently equates OOpenKind with *.  This may or may
 not be a good idea (it's certainly a revolting one) but it DOES NOT WORK
 in the type checker, which *does* need to distinguish OpenKind and *.

 Rather than solve the underlying problem (I have some ideas) I just
 introduced a new, and very short, simple, straightforward function
 TcType.tcEqType to do the job.
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8553#comment:4>
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