AttributeError: 'Function' object has no attribute '_skipped_by_mark'

[elliterate]

If test execution aborts before the skipping module's pytest_runtest_setup hook executes (e.g., via pytest.skip() in an earlier setup hook), the skipping module's pytest_runtest_makereport hook fails with:

AttributeError: 'Function' object has no attribute '_skipped_by_mark'

The skipping module's reporting hook assumes that its setup hook executed and thus that it is safe to read the _skipped_by_mark attribute on the test item. If test execution aborts in an earlier setup hook, however, this assumption will be incorrect and its reporting hook will fail.

Note: This error is the same as seen in #2982 and #2974, but, unlike those issues, is not masking a separate, root error: it is the root error.

Example

Setup

$ python --version
Python 3.6.1

$ pip list
attrs (17.4.0)
pip (9.0.1)
pluggy (0.6.0)
py (1.5.2)
pytest (3.3.1)
setuptools (38.2.5)
six (1.11.0)
wheel (0.30.0)

Note: Also fails on pytest 3.3.0. Succeeds on pytest 3.2.5.

Scenario

conftest.py

import pytest

@pytest.hookimpl(tryfirst=True)
def pytest_runtest_setup(item):
    pytest.skip("manually skipped")

test_skip.py

def test_skipped():
    assert False, "test should be skipped"

Results

$ py.test
======================================================== test session starts ========================================================
platform darwin -- Python 3.6.1, pytest-3.3.1, py-1.5.2, pluggy-0.6.0
rootdir: $HOME/src/skipping, inifile:
collected 1 item

test_skip.py
INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/main.py", line 103, in wrap_session
INTERNALERROR>     session.exitstatus = doit(config, session) or 0
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/main.py", line 141, in _main
INTERNALERROR>     config.hook.pytest_runtestloop(session=session)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 617, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 222, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 216, in <lambda>
INTERNALERROR>     firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 201, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 76, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 180, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/main.py", line 164, in pytest_runtestloop
INTERNALERROR>     item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 617, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 222, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 216, in <lambda>
INTERNALERROR>     firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 201, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 76, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 180, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/runner.py", line 62, in pytest_runtest_protocol
INTERNALERROR>     runtestprotocol(item, nextitem=nextitem)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/runner.py", line 70, in runtestprotocol
INTERNALERROR>     rep = call_and_report(item, "setup", log)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/runner.py", line 157, in call_and_report
INTERNALERROR>     report = hook.pytest_runtest_makereport(item=item, call=call)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 617, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 222, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/__init__.py", line 216, in <lambda>
INTERNALERROR>     firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/pluggy/callers.py", line 196, in _multicall
INTERNALERROR>     gen.send(outcome)
INTERNALERROR>   File "$HOME/.envs/skipping/lib/python3.6/site-packages/_pytest/skipping.py", line 264, in pytest_runtest_makereport
INTERNALERROR>     elif item._skipped_by_mark and rep.skipped and type(rep.longrepr) is tuple:
INTERNALERROR> AttributeError: 'Function' object has no attribute '_skipped_by_mark'

=================================================== no tests ran in 0.01 seconds ====================================================

[pytestbot]

GitMate.io thinks the contributor most likely able to help you is @nicoddemus.

[elliterate]

The fix for this should be as simple as:

diff --git a/_pytest/skipping.py b/_pytest/skipping.py
index a1e5b438..11ddab4d 100644
--- a/_pytest/skipping.py
+++ b/_pytest/skipping.py
@@ -261,7 +261,8 @@ def pytest_runtest_makereport(item, call):
             else:
                 rep.outcome = "passed"
                 rep.wasxfail = explanation
-    elif item._skipped_by_mark and rep.skipped and type(rep.longrepr) is tuple:
+    elif hasattr(item, '_skipped_by_mark') and item._skipped_by_mark and rep.skipped and \
+            type(rep.longrepr) is tuple:
         # skipped by mark.skipif; change the location of the failure
         # to point to the item definition, otherwise it will display
         # the location of where the skip exception was raised within pytest

I'd be happy to submit a pull request, but I was unsure what if any test was appropriate. This seems like a mistake that any hook could make at any time and thus isn't really specific to the skipping plugin.

[RonnyPfannschmidt]

for better consistency i propose the use of getattr(item, '_skipped_by_mark', False)

[RonnyPfannschmidt]

for documentative purposes, https://github.com/pytest-dev/pytest/pull/3075/files#diff-9696819f160fbd3aa8ce9363c38990e9L172 is the line that triggers the issue - the try first hook that skips simply happens before the other call - that detail was my oversight back when switching the variable names

we might want to evaluate the code-base for more such pitfalls in future