[GHC] #14460: Symlink resolving fails against SMB mounts

[GHC]

#14460: Symlink resolving fails against SMB mounts
-------------------------------------+-------------------------------------
        Reporter:  astert            |                Owner:  Phyx-
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.2.1
      Resolution:  fixed             |             Keywords:
Operating System:  Windows           |         Architecture:
 Type of failure:  GHC doesn't work  |  Unknown/Multiple
  at all                             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4216
       Wiki Page:                    |
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Comment (by Vyse007):

 I am still facing this exact issue with 8.4.3.

 On a mounted network drive (shows up as "Network Drive, NTFS" under "This
 PC" on Windows 10), installing GHC and then invoking it throws the
 following error (Z is the networked drive):


 {{{
 PS Z:\sandbox\Vyse\8.4.3> cd .\bin\
 PS Z:\sandbox\Vyse\8.4.3\bin> .\ghci
 ghc.exe: panic! (the 'impossible' happened)
   (GHC version 8.4.3 for x86_64-unknown-mingw32):
         can't decompose ghc.exe path:
 "Z:\\sandbox\\Vyse\\8.4.3\\bin\\ghc.exe"
 }}}

 I originally thought this error must be because `doesDirectoryExist`
 returns false when trying to decompose this path, but that's not the
 case...

 (Note that the `ghci` used below is the one currently on PATH, i.e., not
 on the networked drive)

 {{{
 PS Z:\sandbox\Vyse\8.4.3\bin> ghci
 GHCi, version 8.4.3: http://www.haskell.org/ghc/  :? for help
 Prelude> import System.Directory
 Prelude System.Directory> doesDirectoryExist
 "Z:\\sandbox\\Vyse\\8.4.3\\bin\\"
 True
 }}}

 It might be worth noting that I don't have write permissions for all of
 `Z:\`, but only for my own folder there. I am willing to debug this
 further but I don't really know how to.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14460#comment:18>
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