id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
7656,qsemn001 randomly fails on OS X x86,igloo,,"`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""
}}}
",bug,closed,normal,,libraries/base,7.7,fixed,,,Unknown/Multiple,Unknown/Multiple,None/Unknown,Unknown,,,,