DEP8 test failed with output on stderr

autopkgtest for oneconf failed with there is output to stderr:
"""
+ python3 setup.py nosetests -vv --test test.test_mainfeatures
/usr/lib/python3.3/distutils/dist.py:257: UserWarning: Unknown distribution option: 'test_requires'
  warnings.warn(msg)
......................
----------------------------------------------------------------------
Ran 22 tests in 0.324s

OK
+ python3 setup.py nosetests -vv --test test.test_syncing
/usr/lib/python3.3/distutils/dist.py:257: UserWarning: Unknown distribution option: 'test_requires'
  warnings.warn(msg)
.............................
----------------------------------------------------------------------
Ran 29 tests in 441.769s

OK
+ xvfb-run python3 setup.py nosetests -vv --test test.test_daemon
"""

According do DEP8 specification [1]
"Each test program should, on success, exit with status 0 and print nothing to stderr; if a test exits nonzero, or prints to stderr, it is considered to have failed."

The 2 problems are:
1. debian/tests/unittests is executed with -x
2. output stream is stderr

[1] http://anonscm.debian.org/gitweb/?p=autopkgtest/autopkgtest.git;a=blob_plain;f=doc/README.package-tests;hb=HEAD

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: oneconf 0.3
ProcVersionSignature: Ubuntu 3.8.0-1.5-generic 3.8.0-rc4
Uname: Linux 3.8.0-1-generic x86_64
ApportVersion: 2.8-0ubuntu2
Architecture: amd64
Date: Tue Jan 22 10:03:59 2013
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: oneconf
UpgradeStatus: Upgraded to raring on 2012-01-31 (356 days ago)