[GHC] #15696: Derived Ord instance for enumerations with more than 8 elements seems to be incorrect

[GHC]

#15696: Derived Ord instance for enumerations with more than 8 elements seems to be
incorrect
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        Reporter:  mrkkrp            |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  highest           |            Milestone:  8.6.2
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5196,
       Wiki Page:                    |  Phab:D5201
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Comment (by osa1):

 I understand why it's currently marked as `can_fail`, but if my
 understanding is correct we should be able to mark it as `can_fail =
 False` now. I'm curious why that's causing problems.

 Also, as shown in comment:48, the code is actually better with `can_fail =
 False`.

 >  Are we good to go if you don't make this change?

 I tried to validate now without `can_fail = False`. I'm getting a segfault
 in haddock (when building docs during validate), then in the test suite
 haddock perf tests are failing. Other tests are passing. I'll debug.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15696#comment:52>
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