Tests fail to run: E _tkinter.TclError: no display name and no $DISPLAY environment variable

[yurivict]

Describe the bug

cd /usr/ports/math/py-arviz/work-py39/arviz-0.18.0 && /usr/bin/env -i HOME=/usr/ports/math/py-arviz/work-py39  PWD="${PWD}"  __MAKE_CONF=/nonexistent OSVERSION=1400509 PATH=/usr/local/libexec/ccache:/usr/ports/math/py-arviz/work-py39/.bin:/home/yuri/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin TERM=xterm-256color XDG_DATA_HOME=/usr/ports/math/py-arviz/work-py39  XDG_CONFIG_HOME=/usr/ports/math/py-arviz/work-py39  XDG_CACHE_HOME=/usr/ports/math/py-arviz/work-py39/.cache  HOME=/usr/ports/math/py-arviz/work-py39 PATH=/usr/local/libexec/ccache:/usr/ports/math/py-arviz/work-py39/.bin:/home/yuri/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin PKG_CONFIG_LIBDIR=/usr/ports/math/py-arviz/work-py39/.pkgconfig:/usr/local/libdata/pkgconfig:/usr/local/share/pkgconfig:/usr/libdata/pkgconfig MK_DEBUG_FILES=no MK_KERNEL_SYMBOLS=no SHELL=/bin/sh NO_LINT=YES LDSHARED="cc -shared" PYTHONDONTWRITEBYTECODE= PYTHONOPTIMIZE= PREFIX=/usr/local  LOCALBASE=/usr/local  CC="cc" CFLAGS="-O2 -pipe  -fstack-protector-strong -fno-strict-aliasing "  CPP="cpp" CPPFLAGS=""  LDFLAGS=" -fstack-protector-strong " LIBS=""  CXX="c++" CXXFLAGS="-O2 -pipe -fstack-protector-strong -fno-strict-aliasing  " CCACHE_DIR="/tmp/.ccache" BSD_INSTALL_PROGRAM="install  -s -m 555"  BSD_INSTALL_LIB="install  -s -m 0644"  BSD_INSTALL_SCRIPT="install  -m 555"  BSD_INSTALL_DATA="install  -m 0644"  BSD_INSTALL_MAN="install  -m 444" /usr/local/bin/python3.9 -m pytest -k '' -rs -v -o addopts= 
==================================================================================== test session starts ====================================================================================
platform freebsd14 -- Python 3.9.18, pytest-7.4.4, pluggy-1.4.0 -- /usr/local/bin/python3.9
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase(PosixPath('/usr/ports/math/py-arviz/work-py39/arviz-0.18.0/.hypothesis/examples'))
rootdir: /usr/ports/math/py-arviz/work-py39/arviz-0.18.0
configfile: pytest.ini
plugins: anyio-4.3.0, time-machine-2.11.0, flaky-3.7.0, aspectlib-2.0.0, typeguard-4.1.5, hypothesis-6.98.18, xdoctest-1.1.2, xdist-3.5.0, cov-4.1.0, flakes-4.0.5, timeout-2.1.0, rerunfailures-11.1.2
collected 2922 items / 1 error / 6 skipped                                                                                                                                                  

========================================================================================== ERRORS ===========================================================================================
_____________________________________________________________ ERROR collecting arviz/tests/base_tests/test_plots_matplotlib.py ______________________________________________________________
arviz/tests/base_tests/test_plots_matplotlib.py:138: in <module>
    {"ax": plt.subplots(6, 3)[1]},
/usr/local/lib/python3.9/site-packages/matplotlib/pyplot.py:1598: in subplots
    fig = figure(**fig_kw)
/usr/local/lib/python3.9/site-packages/matplotlib/pyplot.py:934: in figure
    manager = new_figure_manager(
/usr/local/lib/python3.9/site-packages/matplotlib/pyplot.py:465: in new_figure_manager
    return _get_backend_mod().new_figure_manager(*args, **kwargs)
/usr/local/lib/python3.9/site-packages/matplotlib/backend_bases.py:3396: in new_figure_manager
    return cls.new_figure_manager_given_figure(num, fig)
/usr/local/lib/python3.9/site-packages/matplotlib/backend_bases.py:3401: in new_figure_manager_given_figure
    return cls.FigureCanvas.new_manager(figure, num)
/usr/local/lib/python3.9/site-packages/matplotlib/backend_bases.py:1785: in new_manager
    return cls.manager_class.create_with_canvas(cls, figure, num)
/usr/local/lib/python3.9/site-packages/matplotlib/backends/_backend_tk.py:486: in create_with_canvas
    window = tk.Tk(className="matplotlib")
/usr/local/lib/python3.9/tkinter/__init__.py:2270: in __init__
    self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
E   _tkinter.TclError: no display name and no $DISPLAY environment variable
================================================================================== short test summary info ==================================================================================
SKIPPED [1] arviz/tests/helpers.py:649: could not import 'bokeh.plotting': No module named 'bokeh'
SKIPPED [1] arviz/tests/external_tests/test_data_beanmachine.py:14: Ignore beanmachine tests until it supports pytorch 2
SKIPPED [1] arviz/tests/helpers.py:649: could not import 'emcee': No module named 'emcee'
SKIPPED [1] arviz/tests/helpers.py:649: could not import 'jax': No module named 'jax'
SKIPPED [1] arviz/tests/external_tests/test_data_pyjags.py:16: Uses deprecated numpy C-api
SKIPPED [1] arviz/tests/helpers.py:649: could not import 'torch': No module named 'torch'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
================================================================================ 6 skipped, 1 error in 5.88s ================================================================================
*** Error code 2

The DISPLAY variable is set to a valid X11 server when tests are run.

Version: 0.18.0
Python-3.9
FreeBSD 14.0

To Reproduce
Steps to reproduce the behavior. Ideally a self-contained snippet of code, or link to a notebook or external code. Please include screenshots/images produced with ArviZ here, or the stacktrace including arviz code to help.

Expected behavior
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Additional context
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[OriolAbril]

v0.18.0no longer supoorts python 3.9. Is this specific to to 3.9 or does it happen with other versions?

[yurivict]

I have no easy way of verifying this, since we use packaged dependencies w/in the FreeBSD ports tree.

[OriolAbril]

The end of the command you shared is /usr/local/bin/python3.9 -m pytest -k '' -rs -v -o addopts= . Are you required to use this python executable? If so you can't use arviz 0.18.0 and have to use <0.18.0. We aim to roughly follow https://scientific-python.org/specs/spec-0000 guidelines for dropping support for python versions and versions of main scientific python libraries.