#16367: Panic when trying to openFile

#16367: Panic when trying to openFile
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           Reporter:  vilem           |             Owner:  (none)
               Type:  bug             |            Status:  new
           Priority:  normal          |         Milestone:
          Component:  GHCi            |           Version:  8.4.3
           Keywords:                  |  Operating System:  MacOS X
       Architecture:  x86_64 (amd64)  |   Type of failure:  Runtime crash
          Test Case:                  |        Blocked By:
           Blocking:                  |   Related Tickets:
Differential Rev(s):                  |         Wiki Page:
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 {{{
 $ stack repl

 Note: No local targets specified, so a plain ghci will be started with no
 package hiding or package options.

       If you want to use package hiding and options, then you can try one
 of the following:

       * If you want to start a different project configuration than
 /Users/vl200/.stack/global-project/stack.yaml, then you can use stack init
 to create a new
         stack.yaml for the packages in the current directory.

       * If you want to use the project configuration at
 /Users/vl200/.stack/global-project/stack.yaml, then you can add to its
 'packages' field.

 Configuring GHCi with the following packages:
 GHCi, version 8.4.3: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /Users/vl200/.ghci
 Loaded GHCi configuration from
 /private/var/folders/km/1g5b7h891674vhv9z1g4d9cw0000gn/T/haskell-stack-
 ghci/2a3bbd58/ghci-script
 Prelude> import System.IO
 Prelude System.IO> openFile ".g
 .granule    .gitignore  .ghc        .ghci       .gitconfig
 Prelude System.IO> openFile ".granule" Re
 Read           ReadMode       ReadS          ReadWriteMode  Real
 RealFloat      RealFrac       RelativeSeek
 Prelude System.IO> openFile ".granule" ReadMode
 ghc: panic! (the 'impossible' happened)
   (GHC version 8.4.3 for x86_64-apple-darwin):
         nameModule
   system $dShow_a1QJ
   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

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

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16367>