[GHC] #15167: DerivClause list is not populated for (TyConI (DataD ...))

[GHC]

#15167: DerivClause list is not populated for (TyConI (DataD ...))
-------------------------------------+-------------------------------------
        Reporter:  0xd34df00d        |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Template Haskell  |              Version:  8.4.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by bgamari):

 Unfortunately I don't think we currently have a good way to get this
 information. When we are asked to reify the tycon the original Haskell AST
 (which would contain the `deriving` information) that we typechecked to
 produce the type is gone.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15167#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler