[Debian-med-packaging] Bug#813782: python-matplotlib-venn: FTBFS: [failed test] Intersection with the arc along the same circle (which means infinitely many points usually) is reported as no intersection at all.

[Konstantin Tretjakov]

I can't reproduce the bug (apparently it's architecture- or machine-specific), but it is 
indeed due to rounding errors. I modified the test to address this problem and hopefully 
it fixes it.

The updated code is in in github as well as pypi.

Best regards,
Konstantin.

On 13.02.2016 8:01, Andreas Tille wrote:
> Hi,
>
> as you can read below,  one test of the test suite fails.  As far as I
> can see it is possibly a rounding issue rather than a failure.  I wonder
> how the test could be tweaked to pass successfully if you share my
> opinion or what else could be done to pass the test suite successfully.
>
> Kind regards
>
>       Andreas.
>
> On Fri, Feb 05, 2016 at 09:37:32AM +0100, Chris Lamb wrote:
>> Source: python-matplotlib-venn
>> Version: 0.11-2
>> Severity: serious
>>
>> Dear Maintainer,
>>
>> python-matplotlib-venn fails to build from source in unstable/amd64:
>>
>>    [..]
>>
>>    running test
>>    running egg_info
>>    creating matplotlib_venn.egg-info
>>    writing requirements to matplotlib_venn.egg-info/requires.txt
>>    writing matplotlib_venn.egg-info/PKG-INFO
>>    writing top-level names to matplotlib_venn.egg-info/top_level.txt
>>    writing dependency_links to matplotlib_venn.egg-info/dependency_links.txt
>>    writing manifest file 'matplotlib_venn.egg-info/SOURCES.txt'
>>    warning: manifest_maker: standard file 'setup.py' not found
>>
>>    reading manifest file 'matplotlib_venn.egg-info/SOURCES.txt'
>>    writing manifest file 'matplotlib_venn.egg-info/SOURCES.txt'
>>    running build_ext
>>    ============================= test session starts ==============================
>>    platform linux2 -- Python 2.7.11, pytest-2.8.5, py-1.4.31, pluggy-0.3.1 -- /usr/bin/python2.7
>>    cachedir: ../../../.cache
>>    rootdir: /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11, inifile: setup.cfg
>>    collecting ... collected 49 items
>>
>>    matplotlib_venn/_arc.py::matplotlib_venn._arc.Arc.__init__ PASSED
>>    matplotlib_venn/_arc.py::matplotlib_venn._arc.Arc.angle_as_point PASSED
>>    ...
>>    matplotlib_venn/_venn3.py::matplotlib_venn._venn3.venn3 PASSED
>>    matplotlib_venn/_venn3.py::matplotlib_venn._venn3.venn3_circles PASSED
>>
>>    =================================== FAILURES ===================================
>>    _______________ [doctest] matplotlib_venn._arc.Arc.intersect_arc _______________
>>    339         Intersection with the arc along the same circle (which means infinitely many points usually) is reported as no intersection at all.
>>    340
>>    341         >>> a = Arc((0, 0), 1, -90, 90, True)
>>    342         >>> a.intersect_arc(Arc((1, 0), 1, 90, 270, True))
>>    343         [array([ 0.5      , -0.866...]), array([ 0.5      ,  0.866...])]
>>    344         >>> a.intersect_arc(Arc((1, 0), 1, 90, 180, True))
>>    345         [array([ 0.5      ,  0.866...])]
>>    346         >>> a.intersect_arc(Arc((1, 0), 1, 121, 239, True))
>>    347         []
>>    348         >>> a.intersect_arc(Arc((1, 0), 1, 120, 240, True))
>>    Expected:
>>        [array([ 0.5      , -0.866...]), array([ 0.5      ,  0.866...])]
>>    Got:
>>        [array([ 0.5      ,  0.8660254])]
>>
>>    /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/.pybuild/pythonX.Y_2.7/build/matplotlib_venn/_arc.py:348: DocTestFailure
>>    ===================== 1 failed, 48 passed in 0.51 seconds ======================
>>    E: pybuild pybuild:274: test: plugin custom failed with: exit code=1: cp -a README.rst /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/.pybuild/pythonX.Y_2.7/build && cd /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/.pybuild/pythonX.Y_2.7/build && python2.7 /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/setup.py test && rm README.rst
>>    dh_auto_test: pybuild --test --test-pytest -i python{version} -p 2.7 --test --system=custom --test-args=cp -a README.rst {home_dir}/build && cd {home_dir}/build && {interpreter} /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/setup.py test && rm README.rst --dir . returned exit code 13
>
>