[GHC] #12885: "too many iterations" causes constraint solving issue.

[GHC]

#12885: "too many iterations" causes constraint solving issue.
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        Reporter:  judahj            |                Owner:
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.2-rc1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"27a6bdf029491a7bbd50377932ae86ede5b5020a/ghc"
 27a6bdf0/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="27a6bdf029491a7bbd50377932ae86ede5b5020a"
 Test Trac #12885

 ...which is fixed by

   commit 0476a64e70c91b326b53db2fc55adbbaa8e5c270
   Author: Simon Peyton Jones <simonpj at microsoft.com>
   Date:   Tue Oct 25 15:22:17 2016 +0100

     Fix a bug in mk_superclasses_of
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12885#comment:2>
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