[libcxx-commits] [libcxx] Reverts around time_zone (PR #95058)

[Vitaly Buka via libcxx-commits]

vitalybuka wrote:

> It's easy to quote stuff from the Developer Policy out of context. The Developer Policy basically states that it's OK to revert to a green state to keep the CI afloat, and it describes provisions for how people can work together to make progress.
> 
> It doesn't condone reverting a project's work without a reasonable path to fixing the bots, nor does it state that arbitrary

Isn't should be the opposite, if way forward is not clear - revert, then figured, including working with bots maintainers. I always help if to debug on my bots, I can't promise to do that immediately.  So revert and debug AFTER 

We do this all the time on the rest of LLVM, but somehow it's a problem for libcxx. 

>  people can set up arbitrary build bot configurations (on arbitrary hardware and arbitrary machines) and then hold project contributors accountable for failures on these bots to the point of not being able to make progress because of them.
> 

I am rely grateful to people who to setup and maintain those bots. I would rather be slowed down just after landing the patch, then to look into that in 6 month when it reached release on that specific config, and now I am out of context and need to switch from something else. 

I think those arbitrarily bots very helpful in long run.

> Libc++ has a documented support policy and these bots seem to be falling outside of that. I'm not going to play games with you and pretend that we don't have to fix the issues on your bots: we definitely want to get that fixed ASAP. However, since these setups fall outside of our CI, are inaccessible to us and are clearly a bit unusual, we need your help to investigate the issue or provide easy access to the machine so we can reasonably investigate it ourselves. Without that, we'll basically revert these patches, folks will disappear and we'll be left without the ability to re-land the patches.
> 

Yes, that default, sorry if it's not clear.
After revert you should expect to get more information. Isn't how it works for LLVM in general?
E.g. last month I reverted sized new/delete in libcxx, then debugged, and proposed a patch. But debugging was not possible immediately, and we need to recover those bots.

> Once this is over: We work really hard to make our CI as good as possible and covers all of our supported usage scenarios. Please work with us to include your usage scenarios into our pre-commit CI, these events are a huge pain for everyone involved and can be solved with technical means.

Happy to help with CI, but missing CI should not be excuse for no-revert.

https://github.com/llvm/llvm-project/pull/95058