[GHC] #10251: Bad rule generated in pathological cases

[GHC]

#10251: Bad rule generated in pathological cases
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                   Owner:
            Type:  bug               |                  Status:  closed
        Priority:  normal            |               Milestone:  7.10.2
       Component:  Compiler          |                 Version:  7.10.1
      Resolution:  fixed             |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |  deSugar/should_compile/T10251
                                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------

Comment (by simonpj):

 #10389 is another example.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10251#comment:5>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler