Skipping latex tasks does not work when latexmk is not installed

[timmens]

Hey!

As the title says, when I try to skip a task marked with pytask.mark.latex, I get an error unless latexmk is installed. I imagine you already know this, but I've included a use case and an MRE below, nevertheless.

Use Case

I run/develop a project on multiple machines and want to skip latex- related tasks on some of them; and I do not want to install latexmk on them.

MRE

Using pytask's conftest.py:

from pytask import cli, ExitCode
import textwrap


def test_pytask(runner, tmp_path, monkeypatch):
    source = """
    from pathlib import Path
    from pytask import mark

    @mark.skip()
    @mark.latex(script=Path("document.tex"), document=Path("document.pdf"))
    def task_compile_latex_document():
        pass
    """
    # Works with latexmk in PATH.
    tmp_path.joinpath("task_module.py").write_text(textwrap.dedent(source))
    result = runner.invoke(cli, [tmp_path.as_posix()])
    assert result.exit_code == ExitCode.OK

    # Fails with latexmk removed from PATH.
    monkeypatch.setenv("PATH", "")
    tmp_path.joinpath("task_module.py").write_text(textwrap.dedent(source))
    result = runner.invoke(cli, [tmp_path.as_posix()])
    assert result.exit_code == ExitCode.FAILED
    
    # Print error message
    print(result.stdout)

Which produces:

Versions

• pytask: 0.5.1
• pytask-latex 0.4.2
• python: 3.13

[tobiasraabe]

Thanks for the fantastic reproduction! pytask-latex probably checks for latexmk before we evaluate the skip. Maybe we want to check for latexmk only right before the execution.

[timmens]

That would be a nice solution. But wouldn't that imply that, for example, pytask collect won't throw an error if latexmk is not installed (even if there is no skip present)? Though, maybe pytask collect shouldn't raise an error in that case anyway.