[GHC] #10009: type inference regression when faking injective type families

[GHC]

#10009: type inference regression when faking injective type families
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        Reporter:  aavogt            |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  high              |               Milestone:  7.10.1
       Component:  Compiler (Type    |                 Version:  7.10.1-rc1
  checker)                           |                Keywords:
      Resolution:                    |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  GHC rejects       |               Test Case:
  valid program                      |                Blocking:
      Blocked By:                    |  Differential Revisions:
 Related Tickets:                    |
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Comment (by simonpj):

 I was wrong.  I have not fixed it, only a simpler version of it.  So I'm
 not going to get this done this week after all.

 Austin: go ahead and make RC2, don't wait for this.
  * It affects very little code;
  * It can always be fixed by adding a type signature

 I believe that `HList` is the main affected library.  What I don't know is
 whether it affects the ''library itself'' or ''clients of the library''.

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10009#comment:6>
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