Various TestPlotMatplotlib tests fail 0.17.0 on older Debian nd120 (bookworm (and likely Ubuntus )

[yarikoptic]

Tried to update backports for neurodebian to discover that

con-duct_0.17.0-1~nd120+1_amd64.build:FAILED test/test_suite.py::TestPlotMatplotlib::test_matplotlib_plot_info_json
con-duct_0.17.0-1~nd120+1_amd64.build:FAILED test/test_suite.py::TestPlotMatplotlib::test_matplotlib_plot_interactive_backend_with_get_backend
con-duct_0.17.0-1~nd120+1_amd64.build:FAILED test/test_suite.py::TestPlotMatplotlib::test_matplotlib_plot_sanity - ...

and in detail

______________ TestPlotMatplotlib.test_matplotlib_plot_info_json _______________

self = <test_suite.TestPlotMatplotlib testMethod=test_matplotlib_plot_info_json>
mock_plot_save = <MagicMock name='savefig' id='140489145670672'>

    @patch("matplotlib.pyplot.savefig")
    def test_matplotlib_plot_info_json(self, mock_plot_save: MagicMock) -> None:
        """When user passes info.json, usage.json is retrieved and used"""
        args = argparse.Namespace(
            command="plot",
            file_path="test/data/mriqc-example/info.json",
            output="outfile.png",
            func=plot.matplotlib_plot,
            log_level="NONE",
            min_ratio=3.0,
        )
>       assert main.execute(args) == 0
E       AssertionError: assert 1 == 0
E        +  where 1 = <function execute at 0x7fc6a8adafc0>(Namespace(command='plot', file_path='test/data/mriqc-example/info.json', output='outfile.png', func=<function matplotlib_plot at 0x7fc6a8bafba0>, log_level='NONE', min_ratio=3.0))
E        +    where <function execute at 0x7fc6a8adafc0> = main.execute

test/test_suite.py:316: AssertionError
_ TestPlotMatplotlib.test_matplotlib_plot_interactive_backend_with_get_backend _

self = <test_suite.TestPlotMatplotlib testMethod=test_matplotlib_plot_interactive_backend_with_get_backend>
_mock_get_backend = <MagicMock name='get_backend' id='140488678635536'>
mock_show = <MagicMock name='show' id='140488678939536'>

    @patch("matplotlib.pyplot.show")
    @patch("matplotlib.get_backend", return_value="tkagg")
    def test_matplotlib_plot_interactive_backend_with_get_backend(
        self,
        _mock_get_backend: MagicMock,
        mock_show: MagicMock,
    ) -> None:
        """Test that plotting without output in interactive backend calls plt.show() successfully."""
    
        args = argparse.Namespace(
            command="plot",
            file_path="test/data/mriqc-example/usage.json",
            output=None,  # No output file specified
            func=plot.matplotlib_plot,
            log_level="NONE",
            min_ratio=3.0,
        )
        result = main.execute(args)
>       assert result == 0
E       assert 1 == 0

test/test_suite.py:395: AssertionError
________________ TestPlotMatplotlib.test_matplotlib_plot_sanity ________________

self = <test_suite.TestPlotMatplotlib testMethod=test_matplotlib_plot_sanity>
mock_plot_save = <MagicMock name='savefig' id='140488674313680'>

    @patch("matplotlib.pyplot.savefig")
    def test_matplotlib_plot_sanity(self, mock_plot_save: MagicMock) -> None:
        args = argparse.Namespace(
            command="plot",
            file_path="test/data/mriqc-example/usage.json",
            output="outfile.png",
            func=plot.matplotlib_plot,
            log_level="NONE",
            min_ratio=3.0,
        )
>       assert main.execute(args) == 0
E       AssertionError: assert 1 == 0
E        +  where 1 = <function execute at 0x7fc6a8adafc0>(Namespace(command='plot', file_path='test/data/mriqc-example/usage.json', output='outfile.png', func=<function matplotlib_plot at 0x7fc6a8bafba0>, log_level='NONE', min_ratio=3.0))
E        +    where <function execute at 0x7fc6a8adafc0> = main.execute

test/test_suite.py:275: AssertionError

do you see obvious fix? could be tested easily on e.g. docker run --it --rm neurodebian:nd120 and there on env

[yarikoptic]

happens also on ubuntu 24.04

[asmacdo]

@yarikoptic can you provide more information about how you are running these tests? Using docker run -it --rm neurodebian:nd120, my tests passed.

Setup

apt-get update
apt-get install -y python3 python3-pip
apt install python3.11-venv
python3 -m venv venv
source venv/bin/activate
pip install con-duct[all]
apt-get install procps  

**Note: that container didnt have ps installed, procps needed. **

Hand Testing

duct sleep 1
# Fails but with helpful error
con-duct plot .duct/logs/2025.10.08T15.25.08-4639_usage.json 
ERROR:con_duct.suite.plot:Cannot display plot: your current matplotlib backend is agg which is a not a known interactive backend.
ERROR:con_duct.suite.plot:Either set environment variable MPLBACKEND to an interactive backend or use --output to save the plot to a file instead.

This failure makes sense, i dont think we would have an interactive backend inside a docker container.

con-duct plot .duct/logs/2025.10.08T15.25.08-4639_usage.json -o out

This works as expected.

Unit tests (they pass for me) (after reinstall from source)

(venv) root@6ea369ba6b0f:/duct# tox -e py311
py311: install_deps> python -I -m pip install pytest pytest-cov pytest-rerunfailures -e '.[all]'
.pkg: install_requires> python -I -m pip install 'setuptools>=46.4.0' versioningit
.pkg: _optional_hooks> python /path/to/venv/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
.pkg: get_requires_for_build_sdist> python /path/to/venv/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
.pkg: get_requires_for_build_wheel> python /path/to/venv/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
.pkg: prepare_metadata_for_build_wheel> python /path/to/venv/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
.pkg: build_sdist> python /path/to/venv/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
py311: install_package> python -I -m pip install --force-reinstall --no-deps /duct/.tox/.tmp/package/1/con_duct-0.17.0.post11+gfdf4718.tar.gz
py311: commands[0]> pytest test
============================================= test session starts =============================================
platform linux -- Python 3.11.2, pytest-8.4.2, pluggy-1.6.0
cachedir: .tox/py311/.pytest_cache
rootdir: /duct
configfile: tox.ini
plugins: rerunfailures-16.0.1, cov-7.0.0
collected 290 items                                                                                           

test/test_aggregation.py ..............                                                                 [  4%]
test/test_arg_parsing.py ..............                                                                 [  9%]
test/test_e2e.py ........R........                                                                      [ 15%]
test/test_execution.py ..........................                                                       [ 24%]
test/test_formatter.py ..........................................................                       [ 44%]
test/test_log_paths.py ..............                                                                   [ 48%]
test/test_ls.py ............                                                                            [ 53%]
test/test_plot_humanization.py .......................                                                  [ 61%]
test/test_prepare_outputs.py ................                                                           [ 66%]
test/test_report.py ........................                                                            [ 74%]
test/test_schema.py .                                                                                   [ 75%]
test/test_suite.py .................................                                                    [ 86%]
test/test_tailpipe.py ...............                                                                   [ 91%]
test/test_utils.py ...........                                                                          [ 95%]
test/test_validation.py .............                                                                   [100%]

[yarikoptic-test]

all full build logs are in full now at https://neuro.debian.net/_files/_buildlogs/con-duct/0.17.0/ , so you can see what else was installed...

trying to reproduce manually now, and failing did docker run -it --rm neurodebian:nd120

and then there

    8  sed -i -e 's,^deb \(.*\),deb \1\ndeb-src \1,g' /etc/apt/sources.list.d/neurodebian.sources.list
    9  apt-get update -qqq
   11  apt build-dep con-duct -qqq -y
   13  git clone https://github.com/con/duct
   14  apt install -q git tox
   15  git clone https://github.com/con/duct
   16  cd duct
   17  tox 

may be it relates that it was not interactive/scripted?... so placed into script https://www.oneukrainian.com/tmp/build-con-duct.sh, and now running

docker run --rm -v $PWD/build-con-duct.sh:/tmp/build-con-duct.sh neurodebian:nd120 /tmp/build-con-duct.sh

and that didn't work either... so something specific about how debian building happens. I wish we saw more from outputs there -- need to propose to debian package to add -s -v to pytest runs there... but even with them I do not see anything relevant in the logs -- how to adjust test to make it more informative when failing execution?

[yarikoptic]

ok, I have

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> captured log >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
ERROR    con_duct.suite.plot:plot.py:75 con-duct plot missing required dependency: cannot import name 'backend_registry' from 'matplotlib.backends' (/usr/lib/python3/dist-packages/matplotlib/backends/__init__.py)
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> traceback >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

oh -- we have older version, and install newer when interactively!!

root@smaug:/tmp/buildd/con-duct-0.17.0# python3 -c 'from matplotlib.backends import backend_registry'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: cannot import name 'backend_registry' from 'matplotlib.backends' (/usr/lib/python3/dist-packages/matplotlib/backends/__init__.py)
root@smaug:/tmp/buildd/con-duct-0.17.0# apt policy python3-matplotlib
python3-matplotlib:
  Installed: 3.6.3-1+b1
  Candidate: 3.6.3-1+b1
  Version table:
 *** 3.6.3-1+b1 500
        500 http://127.0.0.1:3142/debian bookworm/main amd64 Packages
        100 /var/lib/dpkg/status

so please make it work with that version