[GHC] #12432: TypeInType: open type family application as type family return kind fails to compile

[GHC]

#12432: TypeInType: open type family application as type family return kind fails
to compile
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        Reporter:  j6carey           |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:  duplicate         |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by goldfire):

 * status:  new => closed
 * resolution:   => duplicate


Comment:

 This is due to the fact that GHC processes instances after other type
 declarations. Fixed in HEAD by @alexvieth.

 Workaround: use multiple modules or use an empty top-level declaration
 splice `$(return [])` to force GHC to compile the instances earlier.

 Thanks for reporting!

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12432#comment:1>
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