Bug#999745: systemd: `systemd-run --scope --user` fails with 'No PIDs left'

[Michał Dominiak]

Package: systemd
Version: 249.6-2
Severity: normal
Tags: upstream

Dear Maintainer,

With systemd 249.6-2, the following command does not work:

> systemd-run --scope --user tmux

It fails and logs the following to the journal:

> run-r18e03cbe0b0b4dc19c9093f94edd6310.scope: No PIDs left to attach to the scope's control group, refusing: Success

This used to work on prior versions of systemd. It also fails in an
identical way with any program that I've tried, including /usr/bin/true.
It works without the `--user` flag.

This appears to be related to this commit in upstream:

https://github.com/systemd/systemd-stable/commit/7ecb1b82d9b55a081d81b2802695fd21293ce029

Thanks,
Michał

-- Package-specific info:

-- System Information:
Debian Release: bookworm/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.14.0-4-amd64 (SMP w/16 CPU threads)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_DIE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
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: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages systemd depends on:
ii  adduser          3.118
ii  libacl1          2.3.1-1
ii  libapparmor1     3.0.3-5
ii  libaudit1        1:3.0.6-1
ii  libblkid1        2.37.2-4
ii  libc6            2.32-4
ii  libcap2          1:2.44-1
ii  libcrypt1        1:4.4.26-1
ii  libcryptsetup12  2:2.4.1-1
ii  libgcrypt20      1.9.4-3+b1
ii  libgnutls30      3.7.2-2
ii  libgpg-error0    1.42-3
ii  libip4tc2        1.8.7-1
ii  libkmod2         29-1
ii  liblz4-1         1.9.3-2
ii  liblzma5         5.2.5-2
ii  libmount1        2.37.2-4
ii  libpam0g         1.4.0-10
ii  libseccomp2      2.5.2-2
ii  libselinux1      3.3-1
ii  libsystemd0      249.6-2
ii  libzstd1         1.4.8+dfsg-3
ii  mount            2.37.2-4
ii  util-linux       2.37.2-4

Versions of packages systemd recommends:
ii  dbus [default-dbus-system-bus]   1.12.20-3
ii  systemd-timesyncd [time-daemon]  249.6-2

Versions of packages systemd suggests:
ii  policykit-1        0.105-31
ii  systemd-container  249.6-2

Versions of packages systemd is related to:
ii  dracut           051-1
pn  initramfs-tools  <none>
ii  libnss-systemd   249.6-2
ii  libpam-systemd   249.6-2
ii  udev             249.6-2

-- Configuration Files:
/etc/systemd/logind.conf changed [not included]

-- no debconf information