[Debian-med-packaging] Bug#937698: Help needed for issue in test suite for Python3 (Was: Bug#937698: python-dendropy: Python2 removal in sid/bullseye)

[Simon McVittie]

tl;dr: The issue in the test suite is that there is no test suite.

On Tue, 08 Oct 2019 at 09:28:45 +0200, Andreas Tille wrote:
>   File "/usr/lib/python3/dist-packages/setuptools/command/test.py", line 229, in run
>     self.run_tests()

setuptools is trying to find the tests declared in setup.py:

EXTRA_KWARGS = dict(
    install_requires = ['setuptools'],
    include_package_data = True,
    test_suite = "tests",                        <-- here
    zip_safe = True,
    )

According to <https://setuptools.readthedocs.io/en/latest/setuptools.html>,
setting test_suite like this means: you can import the 'tests' module and
the result is a package or module containing unittest.TestCase subclasses.

However, the tests/ directory (as of python-dendropy_4.4.0-1) does not
contain any Python code at all, only some test data in tests/data/,
so this assertion doesn't seem to be true.

If you look at the buildd logs you'll see that dh_auto_test fails in
Python 2 as well, but the failure is ignored:

https://buildd.debian.org/status/fetch.php?pkg=python-dendropy&arch=all&ver=4.4.0-1&stamp=1527005052&raw=0
> LC_ALL=en_US.utf-8 dh_auto_test || true
> perl: warning: Setting locale failed.
> perl: warning: Please check that your locale settings:
> 	LANGUAGE = (unset),
> 	LC_ALL = "en_US.utf-8",
> 	LANG = (unset)
>     are supported and installed on your system.
> perl: warning: Falling back to the standard locale ("C").
> I: pybuild base:217: python2.7 setup.py test 
...
> running build_ext
> Traceback (most recent call last):
>   File "setup.py", line 192, in <module>
>     **EXTRA_KWARGS
>   File "/usr/lib/python2.7/dist-packages/setuptools/__init__.py", line 129, in setup
>     return distutils.core.setup(**attrs)
>   File "/usr/lib/python2.7/distutils/core.py", line 151, in setup
>     dist.run_commands()
>   File "/usr/lib/python2.7/distutils/dist.py", line 953, in run_commands
>     self.run_command(cmd)
>   File "/usr/lib/python2.7/distutils/dist.py", line 972, in run_command
>     cmd_obj.run()
>   File "/usr/lib/python2.7/dist-packages/setuptools/command/test.py", line 226, in run
>     self.run_tests()
>   File "/usr/lib/python2.7/dist-packages/setuptools/command/test.py", line 248, in run_tests
>     exit=False,
>   File "/usr/lib/python2.7/unittest/main.py", line 94, in __init__
>     self.parseArgs(argv)
>   File "/usr/lib/python2.7/unittest/main.py", line 149, in parseArgs
>     self.createTests()
>   File "/usr/lib/python2.7/unittest/main.py", line 158, in createTests
>     self.module)
>   File "/usr/lib/python2.7/unittest/loader.py", line 130, in loadTestsFromNames
>     suites = [self.loadTestsFromName(name, module) for name in names]
>   File "/usr/lib/python2.7/unittest/loader.py", line 91, in loadTestsFromName
>     module = __import__('.'.join(parts_copy))
> ImportError: No module named tests
> E: pybuild pybuild:336: test: plugin distutils failed with: exit code=1: python2.7 setup.py test
> dh_auto_test: pybuild --test -i python{version} -p 2.7 returned exit code 13
> # need to add true since for Python 3.4 5 tests are failing due some
> # strange encoding problem.  upstream is unable to verify this and
> # there is no better idea for the moment

The failure mode is different in Python 3 because in Python 2, a directory
that does not contain __init__.py cannot be imported as a package (hence
"No module named tests"), but in Python 3, it can. From the backtrace
you gave, presumably the resulting module object has
tests.__file__ == None, which breaks assumptions made by setuptools.

I would suggest removing the test_suite parameter for now, and asking
your upstream to include the test suite in future source code releases.

    smcv