Deferred start of xdist plugin. Is there a way to start xdist in pytest_configure?

[sashko1988]

My environment configuration is defined in the yaml file.
pytest_configure() hook parses that config file and loads necessary stuff.
I want to load xdist based on the content of that file.

How can I make a deferred start of xdist with 8 workers, for example, if the loaded config contains the field processes: 8?

[RonnyPfannschmidt]

Xoud have to ensure your pytest configure hook runs before the one defined in xdist and monkeypatch the settings

Ps Its processes not threads

[sashko1988]

I know that xdist spawns separate processes using execnet. It's just a legacy on my current project. I'm updating the question, so one is confused by the wording.

[sashko1988]

@RonnyPfannschmidt since pytest_configure() can't be wrapped (https://docs.pytest.org/en/stable/reference/reference.html#std-hook-pytest_configure)

This hook is incompatible with hook wrappers.

How can I define execution order?

[RonnyPfannschmidt]

Tryfirst/trylast

[sashko1988]

Thanx, don't know why but I thought Tryfirst/trylast are only for the wrappers.

[RonnyPfannschmidt]

Sometimes examples create accidential bias

[sashko1988]

@RonnyPfannschmidt I think I found a better way.

I moved the parsing of my config file into pytest_cmdline_main() with @pytest.hookimpl(tryfirst=True, wrapper=True).
It stores parsed config in stash, and pytest loads environment as previously in pytest_configure().
Also, pytest_cmdline_main() updates the needed xdist options. In my case, it's only numprocesses and dist.