Discovery of ways to install cython 3

[Nils Bruin]

On a github discussion thread I found that cython 3 can be installed with:

pip install Cython==3.0.0a9

(see https://github.com/cython/cython/issues/4022#issuecomment-937006536 )

Can this be placed a little more prominently in the documentation somewhere?

The documentation at:

https://cython.readthedocs.io/en/latest/src/quickstart/install.html

mentions that the latest release can always be downloaded from https://cython.org/ but I was not able to find any tar of zip there. On https://cython.org/#download I do find that "The latest release of Cython is 3.0 alpha 11 (released 2022-07-31)" but the link to the PyPI package index repository links to Cython 0.29.32.

I was thrown for a bit of a loop to find out how to download a zip for Cython 3.0. I did find a way to get it from github, but the procedure for that is not mentioned in the cython documentation anywhere.

Ideally, of course, Cython would release 3.0, so that Sagemath can transition to it. I understand that the present upgrade to Python 3.10 will have caused a performance degradation due to cython 0.29.32 that is currently used by Sagemath.