RuntimeError is a generic exception which might be raised for many reasons. It might be better to check the Python version instead of relying on exceptions.

grpclib is a library, not a framework, IMO we can't create an event loop on our own, and then make it private. So it must be ok that error will be thrown if there is no event loop in the current context, then it is user's responsibility to create one.

Have you tried to regenerate all requirements files instead of introducing new test_314.txt file?

I tried, but I did not come up with a way to get pip-compile to auto-generate a single file that works with 3.8 and newer versions.

I did another attempt to generate one for 3.9 and use that for Python>=3.9, but it was not compatible with 3.13.

Another approach is to generate a 3.14 file with ; python_version >= "3.14, add ; python_version < "3.14" to the current test.txt, and combine the two files. It feels kind of hacky tho.

Are you okay with generating a new test_314.txt for Python 3.14?

We used to have _compat module: v0.3.2/grpclib/_compat.py

It makes sense to create such module again and move compatibility code there.

Makes sense! I moved this logic to a _compat.py file.