This seems to cause a failure like so

blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir   FAIL       54ms
   Unexpected return code
not equal:
a = 0
b = 3


======================================================================
FAIL: test_mkdir_in_subdir (bzrlib.tests.blackbox.test_versioning.TestVersioning)

vvvv[log from bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir]
329.240  run bzr: ['init']
329.240  bzr arguments: ['init']
329.243  encoding stdout as sys.stdout encoding 'UTF-8'
329.250  creating repository in file:///tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work/.bzr/.
329.253  creating branch <bzrlib.branch.BzrBranchFormat7 object at 0x69da250> in file:///tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work/.bzr/
329.263  trying to create missing lock '/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work/.bzr/checkout/dirstate'
329.263  opening working tree '/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work'
329.270  opening working tree '/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work'
329.272  output:
'Created a standalone tree (format: 2a)\n'
329.272  run bzr: ['mkdir', 'dir']
329.272  bzr arguments: ['mkdir', 'dir']
329.274  encoding stdout as sys.stdout encoding 'UTF-8'
329.278  opening working tree '/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work'
329.283  output:
'added dir\n'
329.283  Run mkdir in subdir
329.283  run bzr: ['mkdir', 'subdir']
329.283  bzr arguments: ['mkdir', 'subdir']
329.285  encoding stdout as sys.stdout encoding 'UTF-8'
329.289  opening working tree '/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work'
329.292  Traceback (most recent call last):
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/commands.py", line 1140, in run_bzr_catch_user_errors
   return run_bzr(argv)
make: *** [check-nodocs] Error 1
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/commands.py", line 1038, in run_bzr
   ret = run(*run_argv)
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/commands.py", line 655, in run_argv_aliases
   return self.run(**all_cmd_args)
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/builtins.py", line 706, in run
   wt.smart_add([dd])
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/mutabletree.py", line 49, in tree_write_locked
   return unbound(self, *args, **kwargs)
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/mutabletree.py", line 403, in smart_add
   kind = osutils.file_kind(abspath)
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/osutils.py", line 1860, in file_kind
   raise errors.NoSuchFile(f)
NoSuchFile: No such file: u'/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work/dir/dir/subdir'

329.293  errors:
"bzr: ERROR: No such file: u'/tmp/testbzr-oemsyS.tmp/bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir/work/dir/dir/subdir'\n"
329.297  opening working tree '/tmp/testbzr-oemsyS.tmp'

^^^^[log from bzrlib.tests.blackbox.test_versioning.TestVersioning.test_mkdir_in_subdir]
----------------------------------------------------------------------
Traceback (most recent call last):
 File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/tests/blackbox/test_versioning.py", line 62, in test_mkdir_in_subdir
   self.run_bzr('mkdir subdir')
AssertionError: Unexpected return code
not equal:
a = 0
b = 3