[GHC] #16080: runTestTT from ghci caused a panic.

[GHC]

#16080: runTestTT from ghci caused a panic.
-------------------------------------+-------------------------------------
           Reporter:                 |             Owner:  (none)
  emacstheviking                     |
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.4.4
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:  x86            |   Type of failure:  Compile-time
                                     |  crash or panic
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Inside a REPL within Emacs+Intero-mode, running a stack project. I am
 writing a simple lexer for fun and I decided to try to see why I wasn't
 getting expected behaviour from an HUnit function.


 {{{
  runTestTT classificationTests
 ghc: panic! (the 'impossible' happened)
   (GHC version 8.4.4 for x86_64-unknown-linux):
         nameModule
   system $dShow_a5Xw
   Call stack:
       CallStack (from HasCallStack):
         callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in
 ghc:Outputable
         pprPanic, called at compiler/basicTypes/Name.hs:241:3 in ghc:Name
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16080>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler