[GHC] #10598: DeriveAnyClass and GND don't work well together

[GHC]

#10598: DeriveAnyClass and GND don't work well together
-------------------------------------+-------------------------------------
        Reporter:  osa1              |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.11
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------

Comment (by goldfire):

 I'm a little confused here. Why is `DeriveAnyClass` failing here? From the
 user manual, it seems `DeriveAnyClass` should ''always'' succeed. I think
 the first step in understanding this all is to figure that out. I've
 hunted around
 (wiki:Commentary/Compiler/GenericDeriving#Usingstandardderivingforgenericfunctions
 and #5462) but I haven't found a proper specification of the feature. It
 certainly isn't in the user manual. Between those two links, one says that
 ''any'' class can be derived, and the other requires a default. Perhaps
 it's the latter. Does anyone out there know? Or do you want to go
 spelunking through the code? One way or the other, we should disentangle
 this and write up a specification.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10598#comment:5>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler