Bug#1115116: systemd-resolved: fails to start on reboot due to missing dependency on /run subdirectory

[LeJacq, Jean Pierre]

Package: systemd-resolved
Version: 257.8-1~deb13u2
Severity: normal

Dear Maintainer,

* What led up to the situation?

After upgrading to trixie, systemd-resolved fails to start on reboot of 
server with this errors logged in journald.

-- Boot 3da14dcf1f4649fb91d6e0c53b02c120 --
Sep 10 10:02:01 vpn00 systemd[1]: systemd-resolved.service: Main process 
exited, code=exited, status=226/NAMESPACE
Sep 10 10:02:01 vpn00 systemd[1]: 5:185m5:185msystemd-resolved.service: 
Failed with result 'exit-code'.
Sep 10 10:02:01 vpn00 systemd[1]: Failed to start 
systemd-resolved.service - Network Name Resolution.
Sep 10 10:02:01 vpn00 systemd[1]: systemd-resolved.service: Scheduled 
restart job, restart counter is at 4.
Sep 10 10:02:01 vpn00 systemd[1]: Starting systemd-resolved.service - 
Network Name Resolution...
Sep 10 10:02:01 vpn00 (resolved)[551]: 5:185m5:185mFailed to create 
destination mount point node '/run/systemd/mount-rootfs/var/tmp', 
ignoring: Read-only file system
Sep 10 10:02:01 vpn00 (resolved)[551]: Failed to mount 
/run/systemd/unit-private-tmp/var-tmp to 
/run/systemd/mount-rootfs/var/tmp: No such file or directory
Sep 10 10:02:01 vpn00 (resolved)[551]: systemd-resolved.service: Failed 
to set up mount namespacing: /var/tmp: No such file or directory
Sep 10 10:02:01 vpn00 (resolved)[551]: systemd-resolved.service: Failed 
at step NAMESPACE spawning /usr/lib/systemd/systemd-resolved: No such 
file or directory
Sep 10 10:02:01 vpn00 systemd[1]: systemd-resolved.service: Main process 
exited, code=exited, status=226/NAMESPACE
Sep 10 10:02:01 vpn00 systemd[1]: 5:185m5:185msystemd-resolved.service: 
Failed with result 'exit-code'.
Sep 10 10:02:01 vpn00 systemd[1]: Failed to start 
systemd-resolved.service - Network Name Resolution.
Sep 10 10:02:01 vpn00 systemd[1]: systemd-resolved.service: Scheduled 
restart job, restart counter is at 5.
Sep 10 10:02:01 vpn00 systemd[1]: 5:185m5:185msystemd-resolved.service: 
Start request repeated too quickly.
Sep 10 10:02:01 vpn00 systemd[1]: 5:185m5:185msystemd-resolved.service: 
Failed with result 'exit-code'.
Sep 10 10:02:01 vpn00 systemd[1]: Failed to start 
systemd-resolved.service - Network Name Resolution.

* What exactly did you do (or not do) that was effective (or
   ineffective)?

The root cause is a missing dependency on the /run kernel mount point. 
The systemd-resolved.service unit file contains?

   /lib/systemd/system/systemd-resolved.service

   [Service]
   PrivateTmp=disconnected

The value "disconnected" means that systemd-resolved will create its 
temporary directories under /run. Because of this, /run must be 
available and writable before systemd-resolved can start.

The problem can be resolved by adding the following to the same unit file:

   [Unit]
   RequiresMountsFor=/run/systemd/mount-rootfs/var/tmp


* What was the outcome of this action?

The proposed change to the unit file resolves the issue. 
systemd-resolved starts correctly after reboot.


-- System Information:
Debian Release: 13.1
   APT prefers stable
   APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-0.deb11.21-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE 
not set
Shell: /bin/sh linked to /usr/bin/dash
Init: unable to detect

Versions of packages systemd-resolved depends on:
ii  dbus [default-dbus-system-bus]  1.16.2-2
ii  libc6                           2.41-12
ii  libssl3t64                      3.5.1-1
ii  libsystemd-shared               257.8-1~deb13u2
ii  systemd                         257.8-1~deb13u2

Versions of packages systemd-resolved recommends:
ii  libidn2-0          2.3.8-2
ii  libnss-myhostname  none
ii  libnss-resolve     257.8-1~deb13u2

Versions of packages systemd-resolved suggests:
pn  polkitd  <none>

-- no debconf information

-- 
JP