When I try to run:
python tools/swarming_client/isolate.py archive -i out/gn/asdf.isolate -s out/gn/asdf2.isolated --isolate-server https://isolateserver.appspot.com

[in this case, asdf.isolate is a minimal test case]

This line hangs forever:
https://cs.chromium.org/chromium/infra/luci/client/utils/oauth.py?type=cs&q=oauth.py&g=0&l=441

According to requests documentation, we should always use a timeout:
http://docs.python-requests.org/en/master/user/quickstart/#timeouts

Oddly enough, once I put a 1-second timeout, everything continues as normal. The response is successfully decoded.