[GHC] #15433: Internal error with PartialTypeSignatures and TH

[GHC]

#15433: Internal error with PartialTypeSignatures and TH
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        Reporter:  monoidal          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Template Haskell  |              Version:  8.4.3
      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:                    |
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Comment (by RyanGlScott):

 Indeed, the renamer normally catches things like `type T = _`, so the
 typechecker never has a chance to get its claws on it. This same
 phenomenon can also be observed in other places where wildcards are
 disallowed (for example, `instance C (Maybe $([t| _ |]))` also gives the
 same internal error).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15433#comment:2>
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