[GHC] #15660: source file modify race leads to inconsistent error message

[GHC]

#15660: source file modify race leads to inconsistent error message
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        Reporter:  joeyhess          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  Poor/confusing    |  Unknown/Multiple
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 I argued for your second option when we were discussion how to implement
 caret diagnostics. However, others made the very reasonable counterpoint
 that this won't work well with CPP. This is unfortunate, but CPP is too
 commonplace to ignore at this point.

 Copying sources to `/tmp` sounds plausible, although could be a bit
 painful to implement.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15660#comment:4>
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