[GHC] #8486: cannot derive new-typeable instances for promoted data types taking parameters

[GHC]

#8486: cannot derive new-typeable instances for promoted data types taking
parameters
-------------------------------------+------------------------------------
        Reporter:  aavogt            |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:  5682
-------------------------------------+------------------------------------

Comment (by goldfire):

 #5682 is now fixed in HEAD, so these instances should indeed be definable.
 I suppose we can be sure that users don't define instances (because they
 wouldn't parse), so if this gets fixed in time in `base`, that might be
 mergeable into 7.8.1.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8486#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler