[GHC] #15441: Data type with phantoms using TypeInType isn't coercible

[GHC]

#15441: Data type with phantoms using TypeInType isn't coercible
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        Reporter:  glittershark      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.2
      Resolution:                    |             Keywords:  Roles
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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Changes (by goldfire):

 * keywords:   => Roles


Comment:

 That looks even more suspect -- my guess is that inferring a phantom there
 wouldn't be sound.

 Hopefully we'll have a worked out theory for roles and dependency in the
 next few months (there's active work going on here), but we're not there
 yet.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15441#comment:4>
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