It seems that they've just released rsa package 4.3 supporting Python 2.7 and 4.4 dropping Python 2.7 to fix the problem. How about waiting for their fix if this is not urgent?

I hope it's fixed now! If there are still issues, please let me know.

@sybrenstuvel Thanks for the quick update. From my local experiments, python2 -m pip install -U rsa installs rsa==4.4, which is still Python 2 incompatible. I think there might be another classifier issue in version 4.4, you might want to "yank" that version, or release a newer Python 2 compatible version.

(Now, the google-auth library breaks again... because rsa==4.4 fits in their narrowed range rsa!=4.1,!=4.1.1,!=4.2,<5,>=3.1.4; python_version < "3".)

FYI, we just released google-auth 1.17.2 with a more restricted pin https://github.com/googleapis/google-auth-library-python/blob/b74168b710da38c0cf06cdf8685c49af4748e3a0/setup.py#L25-L26

@lidizheng I wonder whether we need to backport this fix to the 1.30.x branch? Right now there's not a lot of traffic on the 1.30.x branch, but when we do, I suppose PR would fail these tests in the same way?

@stanley-cheung We won't need to backport this. The breakage is only impacting our test infrastructure. The bad release comes from rsa which is dependency of google-auth which only affect our unit tests.

This PR is a more or less a bandage, long term solution is #23200.