[GHC] #15971: Hadrian fails Shake's linter on Windows

[GHC]

#15971: Hadrian fails Shake's linter on Windows
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        Reporter:  bgamari           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.8.1
       Component:  Build System      |              Version:  8.7
  (Hadrian)                          |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         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 NeilMitchell):

 The correctness criteria for getDirectoryFiles is nuanced - and you're
 actually obeying it - I just write a much simpler "no generated files" one
 in the docs because that's a reasonable safe approximation. As a result,
 I'm not surprised your change doesn't help.

 What we are observing is the modification time changes. I know that on
 some file systems (e.g. NFS) the modification time is cached at a
 different resolution from the resolution it is stored on disk. Is there a
 chance we're hitting this? If so, the only current options are to disable
 lint checking (which is probably fine - maybe leave it on for your dev
 work) or disable use of modification times (which will slow down
 rechecking).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15971#comment:10>
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