[GHC] #9103: hackage's type-level-0.2.4 fails to compile

[GHC]

#9103: hackage's type-level-0.2.4 fails to compile
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        Reporter:  slyfox                     |            Owner:
            Type:  bug                        |           Status:  closed
        Priority:  normal                     |        Milestone:
       Component:  Compiler (Type checker)    |          Version:  7.8.2
      Resolution:  invalid                    |         Keywords:
Operating System:  Unknown/Multiple           |     Architecture:
 Type of failure:  GHC rejects valid program  |  Unknown/Multiple
       Test Case:                             |       Difficulty:  Unknown
        Blocking:                             |       Blocked By:
                                              |  Related Tickets:  #8634
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Comment (by augustss):

 The documentation says 'Both the Paterson Conditions and the Coverage
 Condition are lifted if you give the -XUndecidableInstances flag'.

 This doesn't seem to be the case.  And why does it matter that x is free?
 Can't it just be assumed to be universally quantified?

 It would be nice to get back whatever behaviour the old ghc had, because
 it did the right thing for this case.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9103#comment:2>
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