[GHC] #14907: Error message: (%, %) shows up when with accidental paren

[GHC]

#14907: Error message: (%,%) shows up when with accidental paren
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.5
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Poor/confusing    |  Unknown/Multiple
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5172
       Wiki Page:                    |
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Comment (by Krzysztof Gogolewski <krz.gogolewski@…>):

 In [changeset:"9bfbc4e16d511678cffa9f7f76b369c8cfca7a66/ghc"
 9bfbc4e1/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="9bfbc4e16d511678cffa9f7f76b369c8cfca7a66"
 Don't show constraint tuples in errors (#14907)

 Summary:
 This means that 'GHC.Classes.(%,%)' is no longer mentioned in
 error messages for things like

    class (a,b,c)  -- outside of 'GHC.Classes'
    class (a,Bool)

 Test Plan: make TEST=T14907a && make TEST=T14907b

 Reviewers: RyanGlScott, bgamari

 Reviewed By: RyanGlScott

 Subscribers: rwbarton, carter

 GHC Trac Issues: #14907

 Differential Revision: https://phabricator.haskell.org/D5172
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14907#comment:4>
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