Re: [GHC] #9106: GHC Panic related to functional dependencies - kindFunResult

23 May 2014

      #9106: GHC Panic related to functional dependencies - kindFunResult
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        Reporter:  yuriy               |            Owner:
            Type:  bug                 |           Status:  new
        Priority:  normal              |        Milestone:
       Component:  Compiler            |          Version:  7.8.2
      Resolution:                      |         Keywords:
Operating System:  Windows             |     Architecture:  x86
 Type of failure:  Compile-time crash  |       Difficulty:  Unknown
       Test Case:                      |       Blocked By:
        Blocking:                      |  Related Tickets:
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Comment (by Simon Peyton Jones ):

 In [changeset:"d8d97113c24e7216be36c9cdfc58e91f26528f06/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="d8d97113c24e7216be36c9cdfc58e91f26528f06"
 Make the unifier a fixpoint even for the free kind vars of a tyvar

 The (pure) unifier tcUnifyTys returns an idempotent substitution.
 But previously the kinds of type variables free in the range of
 the subst could have un-substituted kind variables.

 This patch fixes that, fixing Trac #9106.

 See Note [Finding the substitution fixpoint] in Unify
 }}}

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9106#comment:5
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