[GHC] #14898: Panic with repSplitAppTys

[GHC]

#14898: Panic with repSplitAppTys
-------------------------------------+-------------------------------------
        Reporter:  ryanreich         |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:  duplicate         |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13819            |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * status:  infoneeded => closed
 * resolution:   => duplicate
 * related:   => #13819


Comment:

 Now that you mention it, despite ryanreich's message to the contrary, that
 code alone //does// panic on GHC 8.2.1 when put into its own module:

 {{{
 $ /opt/ghc/8.2.1/bin/ghci Bug.hsGHCi, version 8.2.1:
 http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/rgscott/.ghci
 [1 of 1] Compiling Main             ( Bug.hs, interpreted )
 ghc: panic! (the 'impossible' happened)
   (GHC version 8.2.1 for x86_64-unknown-linux):
         repSplitAppTys
   a_a1Ah[sk:1]
   ReaderT r_a1Ag[sk:1] m_a1Af[sk:1] b_a1Ai[sk:1]
   []
   Call stack:
       CallStack (from HasCallStack):
         prettyCurrentCallStack, called at
 compiler/utils/Outputable.hs:1133:58 in ghc:Outputable
         callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in
 ghc:Outputable
         pprPanic, called at compiler/types/Type.hs:808:9 in ghc:Type
 }}}

 But does not with 8.2.2, as sighingnow noted in comment:5. So this really
 is a duplicate of #13819. Hooray!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14898#comment:6>
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