cvxopt testsuite fails with matplotlib-2.1.0

[vbraun]

The cvxopt testsuite should work headless and not try to connect to X:

[cvxopt-1.1.8.p2] Optimal solution found.
[cvxopt-1.1.8.p2] Traceback (most recent call last):
[cvxopt-1.1.8.p2]   File "normappr.py", line 26, in <module>
[cvxopt-1.1.8.p2]     pylab.subplot(311)
[cvxopt-1.1.8.p2]   File "/mnt/disk/home/buildslave-sage/slave/sage_git/build/local/lib/python2.7/site-packages/matplotlib/pyplot.py", line 1052, in subplot
[cvxopt-1.1.8.p2]     fig = gcf()
[cvxopt-1.1.8.p2]   File "/mnt/disk/home/buildslave-sage/slave/sage_git/build/local/lib/python2.7/site-packages/matplotlib/pyplot.py", line 588, in gcf
[cvxopt-1.1.8.p2]     return figure()
[cvxopt-1.1.8.p2]   File "/mnt/disk/home/buildslave-sage/slave/sage_git/build/local/lib/python2.7/site-packages/matplotlib/pyplot.py", line 534, in figure
[cvxopt-1.1.8.p2]     **kwargs)
[cvxopt-1.1.8.p2]   File "/mnt/disk/home/buildslave-sage/slave/sage_git/build/local/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 170, in new_figure_manager
[cvxopt-1.1.8.p2]     return cls.new_figure_manager_given_figure(num, fig)
[cvxopt-1.1.8.p2]   File "/mnt/disk/home/buildslave-sage/slave/sage_git/build/local/lib/python2.7/site-packages/matplotlib/backends/backend_tkagg.py", line 1049, in new_figure_manager_given_figure
[cvxopt-1.1.8.p2]     window = Tk.Tk(className="matplotlib")
[cvxopt-1.1.8.p2]   File "/mnt/disk/home/buildslave-sage/slave/sage_git/build/local/lib/python2.7/lib-tk/Tkinter.py", line 1819, in __init__
[cvxopt-1.1.8.p2]     self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
[cvxopt-1.1.8.p2] _tkinter.TclError: no display name and no $DISPLAY environment variable
[cvxopt-1.1.8.p2] Error: test /mnt/disk/home/buildslave-sage/slave/sage_git/build/local/var/tmp/sage/build/cvxopt-1.1.8.p2/src/examples/doc/chap10/normappr.py failed

[Konrad127123]

Still broken in 8.5.beta2, but #26288 seems to fix this.

[Konrad127123]

Replying to Konrad127123:

Still broken in 8.5.beta2, but #26288 seems to fix this.

Correction: #26288 (upgrading mathplotlib to 2.2.3) doesn't fix it.

#22380 (upgrading cvxopt to 1.2.2) doesn't fix it either and nor does combining both #26288 and #22380.

[Konrad127123]

On Debian unstable this bug is only triggered if the system tk8.6-dev package is installed.

[fbissey]

The spkg goes out of its way to run the examples rather than cvxopt own test suite.

for di in "$CUR"/src/examples/doc/chap* ; do
    echo "Testing in $di"
    cd "$di"
    for i in `ls | grep -v bin` ; do
        echo "Testing $i ..."
        sage-python23 $i
        if [ $? -ne 0 ]; then
            echo >&2 "Error: test $di/$i failed"
            exit 1
        fi
    done
done

But looking at upstream .travis.yml this is what you sould use to run cvxopt's testsuite

script:
  - python -c 'from cvxopt import blas,lapack,glpk,fftw,dsdp,gsl,cholmod,umfpack'
  - py.test --cov=cvxopt tests/

Of course that implies that pytest and some of its components be installed which is not the case of the default sage. But the failure is clearly self inflicted, running as tests something that wasn't meant to be one. Is it also the case in debian?

In this light, what should we do about cvxopt's spkg-check file?

[jhpalmieri]

Let's close this as a duplicate of #28730.