root@zion:/build/matplotlib-3.6.2# PYTHONPATH=build/lib.linux-x86_64-cpython-311 MATPLOTLIBDATA=/build/matplotlib-3.6.2/lib/matplotlib/mpl-data/ MPLCONFIGDIR=. xvfb-run -a python3.11-dbg -m pytest --verbose --full-trace build/lib.linux-x86_64-cpython-311/matplotlib/tests/test_backend_qt.py::test_fig_close                                                                      
Matplotlib is not built with the correct FreeType version to run tests.  Rebuild without setting system_freetype=1 in mplsetup.cfg.  Expect many image comparison failures below.  Expected freetype version 2.6.1.  Found freetype version 2.12.1.  Freetype build type is not local
============================================================================================================================= test session starts ==============================================================================================================================
platform linux -- Python 3.11.1, pytest-7.2.0, pluggy-1.0.0+repack -- /usr/bin/python3.11-dbg
cachedir: .pytest_cache
rootdir: /build/matplotlib-3.6.2, configfile: pytest.ini
collected 1 item                                                                                                                                                                                                                                                               

build/lib.linux-x86_64-cpython-311/matplotlib/tests/test_backend_qt.py::test_fig_close Fatal Python error: Aborted

Current thread 0x00007eff20bb7040 (most recent call first):
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/backends/backend_qt.py", line 145 in _create_qApp
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/backends/backend_qt.py", line 206 in __init__
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/backend_bases.py", line 2822 in create_with_canvas
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/backend_bases.py", line 1703 in new_manager
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/backend_bases.py", line 3510 in new_figure_manager_given_figure
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/backend_bases.py", line 3505 in new_figure_manager
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/pyplot.py", line 359 in new_figure_manager
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/pyplot.py", line 783 in figure
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/_api/deprecation.py", line 454 in wrapper
  File "/build/matplotlib-3.6.2/build/lib.linux-x86_64-cpython-311/matplotlib/tests/test_backend_qt.py", line 45 in test_fig_close
  File "/usr/lib/python3/dist-packages/_pytest/python.py", line 195 in pytest_pyfunc_call
  File "/usr/lib/python3/dist-packages/pluggy/_callers.py", line 39 in _multicall
  File "/usr/lib/python3/dist-packages/pluggy/_manager.py", line 80 in _hookexec
  File "/usr/lib/python3/dist-packages/pluggy/_hooks.py", line 265 in __call__
  File "/usr/lib/python3/dist-packages/_pytest/python.py", line 1789 in runtest
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 167 in pytest_runtest_call
  File "/usr/lib/python3/dist-packages/pluggy/_callers.py", line 39 in _multicall
  File "/usr/lib/python3/dist-packages/pluggy/_manager.py", line 80 in _hookexec
  File "/usr/lib/python3/dist-packages/pluggy/_hooks.py", line 265 in __call__
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 260 in <lambda>
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 339 in from_call
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 259 in call_runtest_hook
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 220 in call_and_report
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 131 in runtestprotocol
  File "/usr/lib/python3/dist-packages/_pytest/runner.py", line 112 in pytest_runtest_protocol
  File "/usr/lib/python3/dist-packages/pluggy/_callers.py", line 39 in _multicall
  File "/usr/lib/python3/dist-packages/pluggy/_manager.py", line 80 in _hookexec
  File "/usr/lib/python3/dist-packages/pluggy/_hooks.py", line 265 in __call__
  File "/usr/lib/python3/dist-packages/_pytest/main.py", line 349 in pytest_runtestloop
  File "/usr/lib/python3/dist-packages/pluggy/_callers.py", line 39 in _multicall
  File "/usr/lib/python3/dist-packages/pluggy/_manager.py", line 80 in _hookexec
  File "/usr/lib/python3/dist-packages/pluggy/_hooks.py", line 265 in __call__
  File "/usr/lib/python3/dist-packages/_pytest/main.py", line 324 in _main
  File "/usr/lib/python3/dist-packages/_pytest/main.py", line 270 in wrap_session
  File "/usr/lib/python3/dist-packages/_pytest/main.py", line 317 in pytest_cmdline_main
  File "/usr/lib/python3/dist-packages/pluggy/_callers.py", line 39 in _multicall
  File "/usr/lib/python3/dist-packages/pluggy/_manager.py", line 80 in _hookexec
  File "/usr/lib/python3/dist-packages/pluggy/_hooks.py", line 265 in __call__
  File "/usr/lib/python3/dist-packages/_pytest/config/__init__.py", line 167 in main
  File "/usr/lib/python3/dist-packages/_pytest/config/__init__.py", line 190 in console_main
  File "/usr/lib/python3/dist-packages/pytest/__main__.py", line 5 in <module>
  File "/usr/lib/python3.11/runpy.py", line 88 in _run_code
  File "/usr/lib/python3.11/runpy.py", line 198 in _run_module_as_main

Extension modules: numpy.core._multiarray_umath, numpy.core._multiarray_tests, numpy.linalg._umath_linalg, numpy.fft._pocketfft_internal, numpy.random._common, numpy.random.bit_generator, numpy.random._bounded_integers, numpy.random._mt19937, numpy.random.mtrand, numpy.random._philox, numpy.random._pcg64, numpy.random._sfc64, numpy.random._generator, matplotlib._c_internal_utils, PIL._imaging, matplotlib._path, kiwisolver, matplotlib._image, PyQt5.QtCore, PyQt5.QtGui, PyQt5.QtWidgets (total: 21)
Aborted

# grep -B1 freetype debian/mplsetup.cfg 
[libs]
system_freetype = 1