[GHC] #13373: Handle long file paths on Windows

[GHC]

#13373: Handle long file paths on Windows
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        Reporter:  ezyang            |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  libraries/base    |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by joeyhess):

 Due to https://ghc.haskell.org/trac/ghc/ticket/13796 it's hard to make ghc
 embed a custom manifest file to enable long filename support. However, use
 -fno-embed-manifest and when running foo.exe, windows will read a side-by-
 side foo.exe.manifest file.

 I tested this with a foo.hs containing main = writeFile (take 300 (cycle
 "a")) "hello"
 Despite the manifest enabling long file support, on Windows 10 that fails
 with "openFile: does not exist".

 Seems that long file support includes CreateFileW, but ghc's openFile uses
 _wsopen, which is not included in the long file support. This makes the
 manifest approach only useful for some subset of programs.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13373#comment:9>
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