[GHC] #7656: qsemn001 randomly fails on OS X x86

[GHC]

#7656: qsemn001 randomly fails on OS X x86
---------------------------------+------------------------------------------
    Reporter:  igloo             |       Owner:                  
        Type:  bug               |      Status:  new             
    Priority:  normal            |   Milestone:                  
   Component:  libraries/base    |     Version:  7.7             
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown    
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
---------------------------------+------------------------------------------
 `qsemn001` randomly fails on OS X x86 (119 times out of 1000), but never
 on Linux amd64 (tried 1000 times).

 e.g.:
 {{{
 $ make CLEANUP=1 TEST=qsemn001 WAY=normal
 python ../../../testsuite/driver/runtests.py  -e ghc_compiler_always_flags
 ="'-fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-
 package-db -rtsopts '" -e ghc_debugged=False -e ghc_with_native_codegen=1
 -e ghc_with_vanilla=1 -e ghc_with_dynamic=1 -e ghc_with_profiling=0 -e
 ghc_with_threaded_rts=1 -e ghc_with_dynamic_rts=1 -e
 ghc_with_interpreter=1 -e ghc_unregisterised=0 -e
 ghc_dynamic_by_default=False -e ghc_with_smp=1 -e ghc_with_llvm=0 -e
 windows=False -e darwin=True -e in_tree_compiler=True -e clean_only=False
 --rootdir=. --config=../../../testsuite/config/ghc -e
 'config.confdir="../../../testsuite/config"' -e
 'config.compiler="/Users/ian/ghc/git/val32/inplace/bin/ghc-stage2"' -e
 'config.ghc_pkg="/Users/ian/ghc/git/val32/inplace/bin/ghc-pkg"' -e
 'config.hp2ps="/Users/ian/ghc/git/val32/inplace/bin/hp2ps"' -e
 'config.hpc="/Users/ian/ghc/git/val32/inplace/bin/hpc"' -e
 'config.gs="gs"' -e 'config.platform="i386-apple-darwin"' -e
 'config.os="darwin"' -e 'config.arch="i386"' -e 'config.wordsize="32"' -e
 'default_testopts.cleanup="1"' -e 'config.timeout=int() or config.timeout'
 -e 'config.timeout_prog="../../../testsuite/timeout/install-
 inplace/bin/timeout"' -e 'config.exeext=""' -e
 'config.top="/Users/ian/ghc/git/val32/testsuite"'  \
                  --only=qsemn001 \
                  \
                  --way=normal \
                  \
                  \

 Timeout is 300
 Found 6 .T files...
 Beginning test run at Sun Feb  3 21:52:50 GMT 2013
 ====> Scanning ./all.T
 ====> Scanning ./Concurrent/all.T
 ====> Scanning ./IO/all.T
 ====> Scanning ./Numeric/all.T
 ====> Scanning ./System/all.T
 ====> Scanning ./Text.Printf/all.T
 =====> qsemn001(normal) 69 of 156 [0, 0, 0]
 cd . && '/Users/ian/ghc/git/val32/inplace/bin/ghc-stage2' -fforce-recomp
 -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts
 -fno-ghci-history -o qsemn001 qsemn001.hs    >qsemn001.comp.stderr 2>&1
 cd . && ./qsemn001    </dev/null >qsemn001.run.stdout
 2>qsemn001.run.stderr
 Wrong exit code (expected 0 , actual 1 )
 Stdout:
 test semn
 test semn2

 Stderr:
 qsemn001: "acb" /= "abc"

 *** unexpected failure for qsemn001(normal)

 OVERALL SUMMARY for test run started at Sun Feb  3 21:52:50 GMT 2013
      156 total tests, which gave rise to
     1068 test cases, of which
        0 caused framework failures
     1067 were skipped

        0 expected passes
        0 had missing libraries
        0 expected failures
        0 unexpected passes
        1 unexpected failures

 Unexpected failures:
    .  qsemn001 [bad exit code] (normal)
 }}}

 The actual failure varies:
 {{{
 $ grep "qsemn001:" out | sort | uniq -c
   30 qsemn001: "acb" /= "abc"
   34 qsemn001: "ba" /= "ab"
   55 qsemn001: "bac" /= "abc"
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7656>
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