A pip ReadTimeoutError against PyPI in CI means the connection opened and then went quiet: the host accepted the request and sent nothing back inside the socket timeout. On GitHub Actions the fix is to raise the timeout the failing pip actually reads and to cache the wheels, because the default is 15 seconds and a cold job downloads everything again.

The recorded run: pip gives up at a 5 second read timeout, the runner raises the timeout to 100 and the retries to 5, and the retried step saves the wheel.

The host in the traceback says which half failed. pip has one timeout for both, it defaults to 15 seconds, and command line flags beat the environment.

What this error means

The install step runs for a while and then ends in a Python traceback, and the line that matters is near the bottom, in the shape "ReadTimeoutError: HTTPSConnectionPool(host='pypi.org', port=443): Read timed out." The host in it tells you which half of the job failed, and the recorded run below names the other one.…