BlockingIOError: [Errno 11] write could not complete without blocking

[codingjoe]

OS: Ubuntu Trusty (travis-ci; container; sudo=false)
Python: 3.6.4  
xdist: n3

There isn't much I can explain, but that this happens to some, but not all our test groups. Happens only with the latest release.

Exception

Traceback (most recent call last):
  File "/home/travis/virtualenv/python3.6.4/bin/py.test", line 11, in <module>
    sys.exit(main())
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/_pytest/config.py", line 59, in main
    return config.hook.pytest_cmdline_main(config=config)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 76, in get_result
    raise ex[1].with_traceback(ex[2])
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/_pytest/main.py", line 131, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/_pytest/main.py", line 100, in wrap_session
    session.exitstatus = doit(config, session) or 0
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 196, in _multicall
    gen.send(outcome)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/_pytest/terminal.py", line 474, in pytest_sessionfinish
    exitstatus=exitstatus)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 201, in _multicall
    return outcome.get_result()
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 76, in get_result
    raise ex[1].with_traceback(ex[2])
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/_pytest/skipping.py", line 313, in pytest_terminal_summary
    tr._tw.line(line)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/py/_io/terminalwriter.py", line 234, in line
    self.write(s, **kw)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/py/_io/terminalwriter.py", line 224, in write
    write_out(self._file, markupmsg)
  File "/home/travis/virtualenv/python3.6.4/lib/python3.6/site-packages/py/_io/terminalwriter.py", line 384, in write_out
    fil.flush()
BlockingIOError: [Errno 11] write could not complete without blocking

requirements.txt

-e git+https://github.com/Thermondo/[email protected]#egg=drf-extensions
-e git+https://[email protected]/Thermondo/[email protected]#egg=thermondo-salesforce
alabaster==0.7.10
amqp==2.2.2
apipkg==1.4
aspy.yaml==1.0.0
astroid==1.6.1
attrs==17.4.0
babel==2.5.2
bandit==1.4.0
beautifulsoup4==4.6.0
billiard==3.5.0.3
bleach==2.1.2
boto3==1.5.4  # pyup: >=1.6
botocore==1.8.18  # pyup: >=1.9
cached-property==1.3.1
cachetools==2.0.1
celery==4.1.0
certifi==2018.1.18
chardet==3.0.4
click==6.7
codecov==2.0.15
contexttimer==0.3.3
coverage==4.4.2
defusedxml==0.5.0
dj-database-url==0.4.2
dj-email-url==0.0.10
django-admin-sortable==2.1.2
django-appconf==1.0.2
django-cache-url==2.0.0
django-configurations==2.0
django-cors-headers==2.1.0
django-crispy-forms==1.7.0
django-debug-toolbar==1.9.1
django-dirtyfields==1.3
django-extensions==1.9.9
django-extra-views==0.9.0
django-filter==1.1.0
django-formtools==2.1
django-fsm==2.6.0
django-fsm-admin==1.2.4
django-fsm-log==1.5.0
django-geoposition==0.3.0
django-health-check==3.4.1
django-heroku-connect==0.8.2
django-js-asset==1.0.0
django-jsonfield==1.0.1
django-localflavor==2.0
django-log-request-id==1.3.2
django-markdownx==2.0.22
django-measurement==3.0.0
django-model-utils==3.1.1
django-mptt==0.9.0
django-oauth-toolkit==1.0.0
django-orderable==5.0.0
django-pgviews==0.5.3
django-phaxio==2.0.0
django-redis==4.8.0
django-reversion==2.0.13
django-reversion-compare==0.8.3
django-s3file==1.2.1
django-select2==6.0.1
django-stdimage==3.0.0
django-storages==1.6.5
django-suit==0.2.25
django-viewflow==1.2.0
django-watson==1.5.0
django-webtest==1.9.2
django==1.11.9
djangorestframework-expander==0.2.3
djangorestframework==3.7.7
djorm-ext-pgfulltext==0.9.3  # pyup: !=0.10
docutils==0.14
drf-compound-fields==1.0.0
execnet==1.5.0
faster-closeio==1.0.0
first==2.0.1
freezegun==0.3.9
geopy==1.11.0
gitdb2==2.0.3
gitpython==2.1.8
google-api-python-client==1.6.5
google-auth-httplib2==0.0.3
google-auth==1.3.0
googlemaps==2.5.1
graphviz==0.8.2
hiredis==0.2.0
hirefire==0.5
html5lib==1.0.1
httplib2==0.10.3
identify==1.0.7
idna==2.6
ijson==2.3
imagesize==0.7.1
isort==4.2.15
isoweek==1.3.3
jinja2==2.10
jmespath==0.9.3
kombu==4.1.0
lazy-object-proxy==1.3.1
lxml==4.1.1
markdown==2.6.11
markupsafe==1.0
mccabe==0.6.1
measurement==2.0.1
model-mommy==1.5.1
money==1.3.0
mpmath==1.0.0
msgcheck==2.9
newrelic==2.100.0.84
nodeenv==1.2.0
numpy==1.14.0
oauth2client==4.1.2
oauthlib==2.0.6
olefile==0.45.1
orderedmultidict==0.7.11
pandas==0.19.2  # pyup: <0.20
pbr==3.1.1
phonenumberslite==8.8.10
pillow==5.0.0
pip-tools==1.11.0
polib==1.1.0
pluggy==0.6.0
pre-commit==1.5.1
progressbar2==3.34.3
psycopg2==2.7.3.2
py==1.5.2
pyasn1-modules==0.2.1
pyasn1==0.4.2
pycodestyle==2.3.1
pycrypto==2.6.1
pydocstyle==2.1.1
pyenchant==2.0.0
pygments==2.2.0
pyjwt==1.5.3
pylint-celery==0.3
pylint-plugin-utils==0.2.6
pylint==1.8.2
pypdf2==1.26.0
pysocks==1.6.8
pytest-cache==1.0
pytest-cov==2.5.1
pytest-django==3.1.2
pytest-forked==0.2
pytest-mock==1.6.3
pytest-rerunfailures==4.0
pytest-test-groups==1.0.3
pytest-translations==2.0.0
pytest-xdist==1.22.0
pytest==3.3.2
python-briefdruckzentrum==0.1.4
python-dateutil==2.6.1
python-utils==2.2.0
python3-openid==3.1.0
pytz==2017.3
pyyaml==3.12
raven==6.5.0
redis==2.10.6
requests-file==1.4.3
requests-mock==1.4.0
requests-oauthlib==0.8.0
requests==2.18.4
rsa==3.4.2
s3transfer==0.1.12
scikit-learn==0.19.1
scipy==1.0.0
selenium==3.8.1
sendwithus==5.0.0
six==1.11.0
slumber==0.7.1
smmap2==2.0.3
snowballstemmer==1.2.1
social-auth-app-django==2.1.0
social-auth-core==1.6.0
sphinx-rtd-theme==0.2.4
sphinx==1.6.5
sphinxcontrib-spelling==4.0.1
sphinxcontrib-websupport==1.0.1
spyne==2.12.14
sqlparse==0.2.4
stevedore==1.28.0
sympy==1.1.1
tabulate==0.8.2
tldextract==2.2.0
twilio==6.10.1
typing==3.6.4
uritemplate==3.0.0
urllib3==1.22
viewflow-extensions==1.2.0
vine==1.1.4
virtualenv==15.1.0
waitress==1.1.0
webencodings==0.5.1
webob==1.7.4
webtest==2.0.29
werkzeug==0.14.1
whitenoise==3.3.1
workdays==1.4
wrapt==1.10.11
wsgi-sslify==1.0.1
xlrd==1.1.0
xmltodict==0.11.0

[codingjoe]

Never mind, happened in an older version too!

[x007007007]

Hi, @codingjoe ,I have same probably, Could you please tell how did you fix it .I run pytest only fail under jenkins .

src/xxxxxxxx/models/job_config_category.py                                                                   9      1      0      0    89%
src/xxxxxxxx/models/platform.py                                                                             13      1      0      0    92%
src/xxxxxxxx/models/team.py                                                                                  9      1      0      0    89%
src/fusion_build_config/models/trigger_frequency.py             Traceback (most recent call last):
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/config.py", line 59, in main
    return config.hook.pytest_cmdline_main(config=config)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 76, in get_result
    raise ex[1].with_traceback(ex[2])
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/main.py", line 131, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/main.py", line 100, in wrap_session
    session.exitstatus = doit(config, session) or 0
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 196, in _multicall
    gen.send(outcome)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/terminal.py", line 476, in pytest_sessionfinish
    exitstatus=exitstatus)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 201, in _multicall
    return outcome.get_result()
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 76, in get_result
    raise ex[1].with_traceback(ex[2])
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pytest_cov/plugin.py", line 262, in pytest_terminal_summary
    terminalreporter.write('\n' + self.cov_report.getvalue() + '\n')
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/terminal.py", line 198, in write
    self._tw.write(content, **markup)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/py/_io/terminalwriter.py", line 224, in write
    write_out(self._file, markupmsg)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/py/_io/terminalwriter.py", line 369, in write_out
    fil.write(msg)
BlockingIOError: [Errno 11] write could not complete without blocking

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/administrator/slave/workspace/AAAAAA/env/bin/pytest", line 11, in <module>
    sys.exit(main())
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/config.py", line 61, in main
    config._ensure_unconfigure()
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/config.py", line 927, in _ensure_unconfigure
    self.hook.pytest_unconfigure(config=self)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 617, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 222, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/__init__.py", line 216, in <lambda>
    firstresult=hook.spec_opts.get('firstresult'),
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 201, in _multicall
    return outcome.get_result()
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 76, in get_result
    raise ex[1].with_traceback(ex[2])
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/pluggy/callers.py", line 180, in _multicall
    res = hook_impl.function(*args)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/terminal.py", line 492, in pytest_unconfigure
    self._report_keyboardinterrupt()
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/terminal.py", line 497, in _report_keyboardinterrupt
    self.write_sep("!", msg)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/_pytest/terminal.py", line 226, in write_sep
    self._tw.sep(sep, title, **markup)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/py/_io/terminalwriter.py", line 211, in sep
    self.line(line, **kw)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/py/_io/terminalwriter.py", line 234, in line
    self.write(s, **kw)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/py/_io/terminalwriter.py", line 224, in write
    write_out(self._file, markupmsg)
  File "/home/administrator/slave/workspace/AAAAAA/env/lib/python3.5/site-packages/py/_io/terminalwriter.py", line 384, in write_out
    fil.flush()
BlockingIOError: [Errno 11] write could not complete without blocking
                                                       14      4      2      0    62%
src/xxxxxxxx/signals.py                                                                                      3      0      0      0   100%
src/xxxxxxxxx/tests/__init__.py                                                                               0      0      0      0   100%
src/xxxxxxxxx/tests/test_branch.py                                             

[codingjoe]

@x007007007 I don't remember ¯_(ツ)_/¯ But reading my comment, I guess I just updated to the latest version of pytest. Sorry I can't be of more help.

[x007007007]

@codingjoe Sorry I don't have clear description my question, I'm run at newest pytest(3.4.2). and I try to switch different version all of them didn't work. I think this issue resolve my question travis-ci/travis-ci#4704.
Hope it helps

[zed]

I've seen the same BlockingIOError on pytest 7.1.2 (the latest).

[sindhujit1]

I have seen this happening sometimes with uwsgi in django.

[codingjoe]

I have seen this happening sometimes with uwsgi in django.

I am curious, is any uwsgi code actually executed in your test suite? That seems rather unlikely to me, in most uses cases people wouldn't spin up a WSGI server during a test run.

[codingjoe]

I've seen the same BlockingIOError on pytest 7.1.2 (the latest).

What OS or CI provider are you using?

[sindhujit1]

@codingjoe For my stuff, uwsgi is used in our prod environment. We use django runsrever in our test environment.