Documentation mistake regarding patch versions

[luigig44]

Related to #1123, docs say the following here

If the exact patch version doesn't matter to you, specifying just the major and minor versions will get you the latest preinstalled patch version. In the previous example, the version spec 3.12 will use the 3.12.2 Python version found in the cache.

I saw that in a Windows action, requesting Python 3.13, on the first (failed) attempt the action used 3.13.4 and on the second attempt it used 3.13.3 (and therefore succeded).

What is the actual behaviour? Could docs be updated to reflect it?

# First attempt
Run actions/setup-python@v2
  with:
    python-version: 3.13
    token: ***
  env:
    default-python: 3.11
Successfully setup CPython (3.13.4)
# Second attempt
...identical...
Successfully setup CPython (3.13.3)

More importantly, once 3.13.5 is cached, is there any guarantee that 3.13.4 won't be provided instead, once every few attempts, making CI fail?

Originally posted by @luigig44 in #1123

[aparnajyothi-y]

Hello @luigig44, Thank you for creating this issue and we will look into it :)

[mahabaleshwars]

Hi @luigig44,
Could you provide the steps to reproduce the issue or share a public repository that replicates it?

[luigig44]

I cannot. Every action run since has reverted to using Py3.13.3 on Windows. I guess 3.13.4 was deleted from the cache due to being broken, which makes sense.

It originally happened here (used 3.13.4) and here (reverted to 3.13.3). Note that these are the same 'run', so identical workflow and code were used, but the later one used an earlier patch.

I can provide the full original logs, but there is nothing of interest other than what I pasted into my original comment.

It seems 'the latest preinstalled patch version' (as refered to in the docs) can move backwards if a previous 'latest' is uninstalled by GitHub, which is fair enough. If anyone can confirm this is what happened, then no update to the docs is necessary.