[GHC] #15860: Hadrian build fails on FreeBSD

[GHC]

#15860: Hadrian build fails on FreeBSD
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        Reporter:  raichoo           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Build System      |              Version:  8.7
  (Hadrian)                          |
      Resolution:                    |             Keywords:
Operating System:  FreeBSD           |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by NeilMitchell):

 @snowleopard: I view printing the call stack when the build fails as very
 useful. Also note that it's not just printing the call stack of Haskell,
 some of those parts are the Shake build call stack. It's printed better in
 the latest version of Shake, as:

 {{{
 Error when running Shake build system:
   at src/Test/Self.hs:27:5-26:
 * Depends on: Main.exe
   at src/Test/Self.hs:48:9-16:
 * Depends on: General/Wait.o
 * Depends on: General/Wait.o General/Wait.hi
 * Raised the exception:
 ...
 }}}

 Which hopefully improves things. I can see two further improvements:

 * Don't print timing information on an error.
 * If the exception is an {{{ErrorCallWithLocation}}} then grab the
 location information and put it in the rest of the stack trace - which
 then puts the stack traces together and the error at the end.

 You can of course override the Shake behaviour entirely by catching the
 {{{ShakeException}}} - but I think the call stack is super helpful.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15860#comment:10>
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