Don't install xbuildenv for pyodide venv command?

[hoodmane]

I am pretty sure it is not needed. And it currently breaks when using a different Python version because we can't find a matching Python virtual environment. We should check that the Python version matches only when building.

[agriyakhetarpal]

Not installing the xbuildenv sounds reasonable to me, but I think we should also consider the fact that it would break a lot of CI jobs downstream, where I (or others) have used pyodide venv without using pyodide xbuildenv install <..> 😅

Would not installing it make it possible to relax pyodide-build's requirement to >=3.9 instead of >=3.12 (or the equivalent Python version in Pyodide at that point in time)?

[hoodmane]

I'm more after relaxing the ==3.12 requirement than the lower bound. I am not sure in how many places we use Python 3.12 features but I don't really feel like removing them...

[hoodmane]

As for breaking tools, as long as we automatically install a xbuildenv before using pyodide build I think it won't break anything?

[ryanking13]

Yes, I think we talked about downloading the pyodide runtime from NPM instead of using the files in xbuildenv (pyodide/pyodide#3730 (comment)).

However, one possible usage of pyodide venv along with pyodide build is building and testing packages against unreleased Pyodide. So we will need to think about how to deploy unreleased Pyodide versions. using xbuildenv was a one good option as we now have a pipeline for releasing nightly xbuildenvs. We'll probably need to split the pipeline for nightly xbuildenv and pyodide runtime then.