Downloads server: "No module named sigstore"

[hugovk]

Another issue from the 3.14.0a1 release:

✅  Removing temporary release branch
Waiting for browser interaction...
💥  Add files to python.org download page
Traceback (most recent call last):
  File "/Users/hugo/github/release-tools/run_release.py", line 1340, in <module>
    main()
  File "/Users/hugo/github/release-tools/run_release.py", line 1336, in main
    automata.run()
  File "/Users/hugo/github/release-tools/run_release.py", line 245, in run
    raise e from None
  File "/Users/hugo/github/release-tools/run_release.py", line 242, in run
    self.current_task(self.db)
  File "/Users/hugo/github/release-tools/release.py", line 126, in __call__
    return getattr(self, "function")(db)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/hugo/github/release-tools/run_release.py", line 966, in run_add_to_python_dot_org
    raise paramiko.SSHException(f"Failed to execute the command: {stderr_text}")
paramiko.ssh_exception.SSHException: Failed to execute the command: /usr/bin/python3: No module named sigstore
**ERROR**
Couldn't determine version of Sigstore CLI

This was trying to run python3 -m sigstore --version on the downloads server to check we have the right version available, but I didn't yet have sigstore installed for my user.

I fixed it by ssh'ing and installing it manually: pip install --user sigstore --break-system-packages

I should be now set, until the next time we get a fresh server install, or a new RM.

---

Ideas for fix:

• adjust what gets installed into the server by default

• or add a check at the start of the script, like where we check for Docker, and fail early with a message saying to install it

• improve documentation about what needs setting up

• or install it as part of the script