[GHC] #12064: tcIfaceGlobal error with existentially quantified types

[GHC]

#12064: tcIfaceGlobal error with existentially quantified types
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        Reporter:  ezyang            |                Owner:  ezyang
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:                    |             Keywords:  hs-boot
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2221
       Wiki Page:                    |
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Comment (by Edward Z. Yang <ezyang@…>):

 In [changeset:"8f6d292746217f1fa9f645ff8d191943af1c5771/ghc" 8f6d292/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="8f6d292746217f1fa9f645ff8d191943af1c5771"
 Fix #12064 by making IfaceClass typechecking more lazy.

 Summary:
 Comes with a test based off of prog006.

 Signed-off-by: Edward Z. Yang <ezyang at cs.stanford.edu>

 Test Plan: validate

 Reviewers: simonpj, austin, bgamari

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D2221

 GHC Trac Issues: #12064
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12064#comment:5>
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