On 11/03/2022 18.08, Marc-Andre Lemburg wrote:
All other platforms
- Only code which either supports a higher-tier platform or is a general improvement may be checked in.
My understanding of that sentence is: PRs which target platforms not listed in PEP 11 may not be checked in.
IMO, it doesn't make sense to prohibit support code in the code base, if there is community interest in this. By dropping that line, we wouldn't have a problem and also don't need to list platforms in a tier 4 section, since it's still possible to add support in the main code base, without having a core dev maintain it.
Community interest is not sufficient. A supported platform needs active engagement and contributions by the community or vendor. At a bare minimum a platform needs a core developer, who is interested in the platform, and a credible statement, that a buildbot will be provided in the near future.
Please note that the text of the rule is "may be checked in", not "core devs are forbidden to check in". There is a gray area for trivial patches or aspiring platforms. The rule gives us an easy way to refuse patches that cannot be tested. It also gives vendors a list of requirements as well as motivation to contribute buildbots.