[GHC] #12692: Can't find interface-file decl with Typeable

[GHC]

#12692: Can't find interface-file decl with Typeable
-------------------------------------+-------------------------------------
        Reporter:  crockeea          |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.0.2
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  duplicate         |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash                              |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #12132            |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * status:  new => closed
 * resolution:   => duplicate
 * related:   => #12132
 * milestone:   => 8.0.2


Comment:

 This is really #12132 in disguise (which has been fixed in GHC 8.0.2 and
 HEAD). You can see this by observing the output of compiling `Main` with
 `-ddump-splices`:

 {{{
 [3 of 3] Compiling Main             ( Main.hs, interpreted )
 Main.hs:7:3-26: Splicing declarations
     sequence [ppDec $ (2, 1)]
   ======>
     type PP2 = PP '(P (PosBin.D0 PosBin.B1), PosBin.O)
 }}}

 The key part is that `PP2` contains a promoted boxed tuple, and the error
 happens when you try to get the `Typeable` instance for it.

 In any case, this has already been fixed, and it'd be impractical to
 create a regression test from all of this `singletons` code, so I'll just
 close this as a duplicate.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12692#comment:2>
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