> NixOS has system-wide tests that run on PRs, and go green if they pass. E.g. upgrade OpenSSH will trigger a suite of VMs to start, each running OpenSSH in different configurations, and checking they work as expected. These run automatically, are visible to contributors/reviewers, and take O(minutes) to complete. They run on automated backport PRs too.

That concept is not new to stable distro's either. Though the OpenSSH package doesn't do that level of testing in Debian, their tests are here: https://salsa.debian.org/ssh-team/openssh/-/tree/master/debi...

> Bravo. But I don't think it's controversial to suggest that, on average, the closer a person is to upstream version, the more likely they will be to have the motivation and success in making a contribution that works you and upstream.

This mindset makes no sense to me. A bug is a bug is a bug.