@danderson from my perspective as a systemd person I wouldn't ask for that from glibc. We have nss-systemd these days which is an IPC frontend to the generic varlink IPC API described here:
https://systemd.io/USER_GROUP_API
Anyone can plug in their stuff there. It's generic, extensible and IPC based. Unless you are a systemd hater I see no reason why we'd need to shove that into glibc.
@pid_eins Ooh, TIL! I didn't know about this entire subsystem of systemd. My worry was going to be what to do with the cursed legacy modules that some people have, but I see with userdbd there's bidirectional compatibility between varlink and nss clients. Very nice, and yes I agree this is a better way to set up the system.
I look forward to the posts for next release, I'm even learning stuff about older releases!