Make run --python work with virtualenv for Scala Native

[kiendang]

Make run --python work inside virtualenv for Scala Native by setting the SCALAPY_PYTHON_PROGRAMNAME to the path to the Python interpreter. This already works for JVM. For more details see #1270 (comment) and scalapy/scalapy#200.

[alexarchambault]

Thanks @kiendang!

Wondering if there would be a way to add non-regression tests for that… (likely in RunTestDefinitions) Maybe we could setup Python the same way ScalaPy does on its CI?

[kiendang]

Currently virtualenv test in ScalaPy is WIP, part of scalapy/scalapy#303. I'm still not sure what's the best way to do this. The way I used to do it is to

• create a venv
• install a dummy package into a venv
• activate the venv
• test if scalapy can import the package

something like this script https://github.com/scalapy/sbt-scalapy/blob/e8bb194d8277ccb60b6b42545be047702c7380db/scripts/virtualenv_test.sh
I'm not sure if we can do something like that here.

[alexarchambault]

Merging this so that it's part of 0.1.16. We can always add non regression tests for it later…