[GHC] #13393: GHC panic: No skolem info

[GHC]

#13393: GHC panic: No skolem info
-------------------------------------+-------------------------------------
           Reporter:  sheyll         |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.2
           Keywords:                 |  Operating System:  Linux
       Architecture:  x86_64         |   Type of failure:  Compile-time
  (amd64)                            |  crash or panic
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 I got this GHC output:

 {{{
 /home/sven/DEV_LBM/lbm-talk-flow/mediabus-fdk-
 aac/src/Data/MediaBus/Audio/FdkAac/Encoder.hs:124:8: error:ghc: panic!
 (the 'impossible' happened)
   (GHC version 8.0.2 for x86_64-unknown-linux):
         No skolem info: k_ataY[sk]

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

 }}}

 It happens when I omit a type signature.

 We do not have the resources right now to create a minimal test case, but
 I didn't want to ignore the request to file a bug report.

 This happens in a small project available on github, I commited the
 specific code and tagged the commit 'ghc-panic' and added a comment in the
 code.

 I doubt that is makes sense to paste the code here, so if anyone looks
 into this, please grab the code from github at:
 [https://github.com/lindenbaum/mediabus-fdk-aac/blob/ghc-
 panic/src/Data/MediaBus/Audio/FdkAac/Encoder.hs]

 Sorry if this bug report is not helpful.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13393>
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