Re: bug#64937: "who" reports funny dates

[Paul Eggert]

On 2023-08-08 05:24, Thorsten Kukuk wrote:

> Something emacs needs to get fixed. On musl libc systems like Alpine,
> you don't have utmp nor wtmp.

Yes, as Bruno mentioned, we know of no way to find the boot time on 
Alpine. When Emacs cannot determine the boot time, it pretends that the 
system booted in 1970.


> Beside that the emacs heuristic to find backups of wmtp is very
> questionable, it wouldn't match on any of my systems.

It should work on our department's old Solaris 10 system, which has 
files /var/adm/wtmpx, /var/adm/wtmpx.0, /var/adm/wtmpx.1, ..., 
/var/adm/wtmpx.9, each about a week older than its predecessor.


> There are better ways to determine the boot time.

If we could find these better ways, we could add them to Emacs etc. In 
the meantime I'm not sure what we can do. As Bruno mentioned, 
CLOCK_BOOTTIME doesn't work either. This area is a bit of a mess.


> Does they really maintain btmp or is it just openssh, where you cannot
> disable btmp entries?

Ubuntu 23.04 really maintains btmp. I just now deliberately used the 
wrong password on a console, and an entry was created in btmp.


> I know that Fedora tries to maintain it via pam_lastlog.so, but do to
> all the problems with this interface that module is deprecated and will
> be removed in a future release.

Perhaps they'll remove it in 2038. :-) In the meantime, we still need a 
substitute for utmp, wtmp, and btmp.