[GHC] #15172: Undecidable instances slip through

[GHC]

#15172: Undecidable instances slip through
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        Reporter:  simonpj           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.2.2
      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:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"af0757de4649ca562a0e9a624ebef155113531ab/ghc"
 af0757de/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="af0757de4649ca562a0e9a624ebef155113531ab"
 Check for type families in an instance context

 This patch adds a check for type families to the instance-decl
 termination check.  See Note [Type families in instance contexts]
 and Trac #15172.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15172#comment:2>
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