Somehow I feel like every system that I want to keep updated stays on an old version, and every system that I want to keep pinned to some version just force-feeds me its updates...
There is backports, and I've thought about maintaining a newer Python interpreter in backports (when I was working for a company using Jessie and trying to use a Debian stack for everything and sort of wanting async syntax). You could introduce python3.6 or python3.7 as a new package in backports. But it would be extremely hard to update the Python modules in Debian to the newer version, too, because there's just a "python3-foo" package for each module, so you'd either have to recompile all binary modules and patch them to work on the newer Python as necessary (and patch anything using async or await as regular identifiers....), or you'd have to introduce an interpreter that intentionally wasn't compatible with modules installed as Debian packages. (Or you could introduce an interpreter that tried its best and failed randomly, which seems worse than either option.) I'm personally sympathetic to wanting to get /usr/bin/python3.6 from my OS even if the only useful thing to do is put a virtualenv on top, but I think it makes sense to just install Python yourself into /usr/local at that point.
Re latexmk, it looks like the volunteer maintainer hasn't updated it since 2015, and there's a culture of not stepping on people's toes and waiting a while before assuming they're inactive or no longer care. But it's been updated in the development release. The current changelog https://metadata.ftp-master.debian.org/changelogs/main/l/lat... has a bunch of "NMU" entries, non-maintainer uploads.
Re latexmk: so am I getting the development release on Arch? I get the 2018 version with texlive-core.
Downvoters: If you're honest, then do your homework instead of downvoting. If you're dishonest, and you're trying to cover it up, shame on you--you're as bad as the abusers in Debian.
Ah, yes, the standard bureaucratic cover for abuse: retroactively justify it with formal committee action, by asking people to submit examples of badthink and badspeak from years ago:
2012: 1 email
2013: 7 emails
2014: 5 emails
2015: 1 email
2016: 0 emails
2017: 2 emails
2018: 2 emails
No, Debian stable doesn't get bugfixes, only if those bugfixes are for security issues! (or some really severe bugs)
Example: Debian's Python is still 3.4.2, not 3.4.9!
But I wouldn't want Debian to change their release behavior. And to be honest regarding different versions: Python has always been a special needs kid in this regard.
Spot on.