[GHC] #12441: Conflicting definitions error does not print explicit quantifiers when necessary

[GHC]

#12441: Conflicting definitions error does not print explicit quantifiers when
necessary
-------------------------------------+-------------------------------------
        Reporter:  ezyang            |                Owner:  philderbeast
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  warning at compile-time            |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2734
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"33140f41b931fb81bf2e5aa28603fe757bb3779d/ghc" 33140f4/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="33140f41b931fb81bf2e5aa28603fe757bb3779d"
 Show explicit quantifiers in conflicting definitions error

 This fixes #12441, where definitions in a Haskell module and its boot
 file which differed only in their quantifiers produced a confusing error
 message. Here we teach GHC to always show quantifiers for these errors.

 Reviewers: goldfire, simonmar, erikd, austin, hvr, bgamari

 Reviewed By: bgamari

 Subscribers: snowleopard, simonpj, mpickering, thomie

 Differential Revision: https://phabricator.haskell.org/D2734

 GHC Trac Issues: #12441
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12441#comment:7>
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