[GHC] #16219: Backpack - TH+indefinite module interface file error

[GHC]

#16219: Backpack - TH+indefinite module interface file error
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        Reporter:  lightandlight     |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.7
      Resolution:                    |             Keywords:  backpack
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5475
       Wiki Page:                    |
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Comment (by ezyang):

 So, hypothetically, it might be possible to get TH for modules which don't
 transitively depend on a signature in the indefinite package. But,
 fundamentally, there's no way to have TH which depends on a signature,
 since the TH splice affects type checking, but you have no idea what the
 actual implementation of the splice is!

 You can always work around these problems by making more packages. Maybe
 if you say more about your use case I might be able to better advise.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16219#comment:9>
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