$ sudo apt-get build-dep python3-matplotlib python3-matplotlib-venn$ pip install -e .[dev,extra,all]$ pytest========================================== test session starts ==========================================platform linux -- Python 3.8.2, pytest-5.4.1, py-1.5.4, pluggy-0.13.1rootdir: /home/werner/Public/hpc/tools/matplotlib.git, inifile: pytest.ini, testpaths: libplugins: cov-2.8.1, datadir-1.3.1, regressions-1.0.6, timeout-1.3.4collected 7591 items     [...]================================================ FAILURES =================================================___________________________________________ test_pdflatex[pdf] ____________________________________________expected = '/home/werner/Public/hpc/tools/matplotlib.git/result_images/test_backend_pgf/pgf_pdflatex-expected.pdf'actual = PosixPath('/home/werner/Public/hpc/tools/matplotlib.git/result_images/test_backend_pgf/pgf_pdflatex.pdf')tol = 0    def _raise_on_image_difference(expected, actual, tol):        __tracebackhide__ = True            err = compare_images(expected, actual, tol, in_decorator=True)        if err:            for key in ["actual", "expected"]:                err[key] = os.path.relpath(err[key])>           raise ImageComparisonFailure(                'images not close (RMS %(rms).3f):\n\t%(actual)s\n\t%(expected)s '                 % err)E           matplotlib.testing.exceptions.ImageComparisonFailure: images not close (RMS 11.669):E           result_images/test_backend_pgf/pgf_pdflatex_pdf.pngE           result_images/test_backend_pgf/pgf_pdflatex-expected_pdf.pnglib/matplotlib/testing/decorators.py:135: ImageComparisonFailure______________________________________________ test_rcupdate ______________________________________________    @needs_xelatex    @needs_pdflatex    @pytest.mark.skipif(not _has_sfmath(), reason='needs sfmath.sty')    @pytest.mark.style('default')    @pytest.mark.backend('pgf')    def test_rcupdate():        rc_sets = [{'font.family': 'sans-serif',                    'font.size': 30,                    'figure.subplot.left': .2,                    'lines.markersize': 10,                    'pgf.rcfonts': False,                    'pgf.texsystem': 'xelatex'},                   {'font.family': 'monospace',                    'font.size': 10,                    'figure.subplot.left': .1,                    'lines.markersize': 20,                    'pgf.rcfonts': False,                    'pgf.texsystem': 'pdflatex',                    'pgf.preamble': ('\\usepackage[utf8x]{inputenc}'                                     '\\usepackage[T1]{fontenc}'                                     '\\usepackage{sfmath}')}]        tol = [6, 0]        for i, rc_set in enumerate(rc_sets):            with mpl.rc_context(rc_set):                create_figure()>               compare_figure('pgf_rcupdate%d.pdf' % (i + 1), tol=tol[i])lib/matplotlib/tests/test_backend_pgf.py:157: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _fname = 'pgf_rcupdate2.pdf', savefig_kwargs = {}, tol = 0    def compare_figure(fname, savefig_kwargs={}, tol=0):        actual = os.path.join(result_dir, fname)        plt.savefig(actual, **savefig_kwargs)            expected = os.path.join(result_dir, "expected_%s" % fname)        shutil.copyfile(os.path.join(baseline_dir, fname), expected)        err = compare_images(expected, actual, tol=tol)        if err:>           raise ImageComparisonFailure(err)E           matplotlib.testing.exceptions.ImageComparisonFailure: Error: Image files did not match.E             RMS Value: 13.166575390337284E             Expected:  E               /home/werner/Public/hpc/tools/matplotlib.git/result_images/test_backend_pgf/expected_pgf_rcupdate2_pdf.pngE             Actual:    E               /home/werner/Public/hpc/tools/matplotlib.git/result_images/test_backend_pgf/pgf_rcupdate2_pdf.pngE             Difference:E               /home/werner/Public/hpc/tools/matplotlib.git/result_images/test_backend_pgf/pgf_rcupdate2_pdf-failed-diff.pngE             Tolerance: E               0lib/matplotlib/tests/test_backend_pgf.py:63: ImageComparisonFailure____________________________________________ test_usetex[png] _____________________________________________expected = '/home/werner/Public/hpc/tools/matplotlib.git/result_images/test_usetex/test_usetex-expected.png'actual = PosixPath('/home/werner/Public/hpc/tools/matplotlib.git/result_images/test_usetex/test_usetex.png')tol = 0    def _raise_on_image_difference(expected, actual, tol):        __tracebackhide__ = True            err = compare_images(expected, actual, tol, in_decorator=True)        if err:            for key in ["actual", "expected"]:                err[key] = os.path.relpath(err[key])>           raise ImageComparisonFailure(                'images not close (RMS %(rms).3f):\n\t%(actual)s\n\t%(expected)s '                 % err)E           matplotlib.testing.exceptions.ImageComparisonFailure: images not close (RMS 12.877):E           result_images/test_usetex/test_usetex.pngE           result_images/test_usetex/test_usetex-expected.pnglib/matplotlib/testing/decorators.py:135: ImageComparisonFailure========================================= short test summary info =========================================FAILED lib/matplotlib/tests/test_backend_pgf.py::test_pdflatex[pdf] - matplotlib.testing.exceptions.Imag...FAILED lib/matplotlib/tests/test_backend_pgf.py::test_rcupdate - matplotlib.testing.exceptions.ImageComp...FAILED lib/matplotlib/tests/test_usetex.py::test_usetex[png] - matplotlib.testing.exceptions.ImageCompar...=================== 3 failed, 7517 passed, 60 skipped, 11 xfailed in 630.55s (0:10:30) ====================