t5310 broken under Mac OS

["Torsten Bögershausen" <tboegi@web.de>]

One test case fails here,
but I am to tired to dig further.


ok 42 - pack reuse respects --incremental

expecting success:
     git repack -ad &&
     git rev-list --use-bitmap-index --count --all >expect &&
     bitmap=$(ls .git/objects/pack/*.bitmap) &&
     test_when_finished "rm -f $bitmap" &&
     head -c 512 <$bitmap >$bitmap.tmp &&
     mv $bitmap.tmp $bitmap &&
     git rev-list --use-bitmap-index --count --all >actual 2>stderr &&
     test_cmp expect actual &&
     test_i18ngrep corrupt stderr

override r--r--r--  tb/staff for 
.git/objects/pack/pack-8886db3fce4f9657c1a43fee7d3ea4f2a4b5be2d.bitmap? 
(y/n [n]) not overwritten
error: 'grep corrupt stderr' didn't find a match in:
<File 'stderr' is empty>
not ok 43 - truncated bitmap fails gracefully
#
#        git repack -ad &&
#        git rev-list --use-bitmap-index --count --all >expect &&
#        bitmap=$(ls .git/objects/pack/*.bitmap) &&
#        test_when_finished "rm -f $bitmap" &&
#        head -c 512 <$bitmap >$bitmap.tmp &&
#        mv $bitmap.tmp $bitmap &&
#        git rev-list --use-bitmap-index --count --all >actual 2>stderr &&
#        test_cmp expect actual &&
#        test_i18ngrep corrupt stderr
#

# failed 1 among 43 test(s)
1..43