[GHC] #13272: DeriveAnyClass regression involving a rigid type variable

[GHC]

#13272: DeriveAnyClass regression involving a rigid type variable
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.4.1
       Component:  Compiler (Type    |              Version:  8.1
  checker)                           |
      Resolution:                    |             Keywords:  Generics
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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Comment (by RyanGlScott):

 > Isn't it better now in other ways, though?

 That's true. I really don't know how many pieces of code in the wild
 actually structure their default type signatures in a way that's analogous
 to the original program, so if not too many folks complain about it during
 the 8.2 release candidate window, I suppose we could deem
 639e702b6129f501c539b158b982ed8489e3d09c a net positive and live with it
 for now.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13272#comment:7>
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