Your message dated Thu, 28 Aug 2025 12:27:03 -0400
with message-id <[email protected]>
and subject line Re: Bug#1112334: coreutils: systemd integration broke "who" in
trixie/sysvinit --- workaround
has caused the Debian Bug report #1112334,
regarding coreutils: systemd integration broke "who" in trixie/sysvinit ---
workaround
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
1112334: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1112334
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: coreutils
Version: 9.7-3
Severity: normal
Tags: upstream
TLDR
$ who | wc -l
0
$ who /var/run/utmp | wc -l
0
$ who /var/run/./utmp | wc -l
10
$ alias who='who /run/utmp'
$ who /run/utmp | wc -l
10
/TLDR
In lib/readutmp.c (gnulib), read_utmp() invokes read_utmp_from_systemd()
instead of read_utmp_from_file() when the <file> parameter equals the
default utmp filename "/var/run/wtmp":
1 int
2 read_utmp (char const *file, idx_t *n_entries, STRUCT_UTMP **utmp_buf,
3 int options)
4 {
5 # if READUTMP_USE_SYSTEMD
6 if (strcmp (file, UTMP_FILE) == 0)
7 /* Imitate reading UTMP_FILE, using systemd and Linux APIs. */
8 return read_utmp_from_systemd (n_entries, utmp_buf, options);
9 # endif
In turn read_utmp_from_systemd() ignores all entries from the utmp file,
at least when no seat manager is running, and possibly also in other
scenarios.
The READUTMP_USE_SYSTEMD macro is defined during the configure phase
(m4/readutmp.m4), depending on the test program
#include <stdint.h>
#include <systemd/sd-login.h>
int main() {
uint64_t st;
sd_session_get_start_time ("1", &st);
}
which fails to compile in bookworm (because sd_session_get_start_time()
is not available in libsystemd 252.38), but unfortunately succeeds in
trixie (libsystemd 257.7).
However, line 6 above permits a workaround: use a different filename
from the predefined UTMP_FILE.
RANT
Upstream made a number of decisions that IMHO are not very brilliant:
- entangle core utilities with a library belonging to a specific
init/service-manager implementation
- change the behaviour of the (POSIX standard) "who" utility without making
the change opt-in, or at least providing an option/env-var to restore the
classic behaviour
- ignore user intent on "who <filename>" if filename happens to be the
usual one or empty (default)
- accept the fact that `"who" needs to ask seat manager', because
of course the best way to read a file is through an IPC to a daemon that
might not be running on the system.
/RANT
Best regards,
g.b. (a greybeard)
-- System Information:
Debian Release: 13.0
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 6.12.41+deb13-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=C, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled
Versions of packages coreutils depends on:
ii libacl1 2.3.2-2+b1
ii libattr1 1:2.5.2-3
ii libc6 2.41-12
ii libcap2 1:2.75-10+b1
ii libgmp10 2:6.3.0+dfsg-3
ii libselinux1 3.8.1-1
ii libssl3t64 3.5.1-1
ii libsystemd0 257.7-1
coreutils recommends no packages.
coreutils suggests no packages.
-- no debconf information
--- End Message ---
--- Begin Message ---
On Thu, Aug 28, 2025 at 05:18:12PM +0200, g1 wrote:
Upstream made a number of decisions that IMHO are not very brilliant:
upstream didn't have a lot of options. I was in the same position,
because even though I thought dropping utmp for trixie was a mistake, it
happened anyway and even though some utilities are still writing utmp
entries, most are not. I really wish that trixie had supported both
options, but when systemd changed unilaterally this outcome was forced.
--- End Message ---
