Wrongly configured org.freedesktop.systemd1 service on user's dbus session with i3

[DamienCassou]

Describe the bug

The dbus service org.freedesktop.systemd1 doesn't seem properly started when lightdm+i3 is used.

To Reproduce

$ busctl --user status org.freedesktop.systemd1
Failed to get credentials: No such device or address

Expected behavior
Doing the same within an lightdm+i3 session results in:

$ busctl --user status org.freedesktop.systemd1
PID=1899
PPID=1
[...]

Notify maintainers

/cc @ocharles @worldofpeace @modulistic @fpletz @globin

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

• system: "x86_64-linux"
• host os: Linux 5.4.35, NixOS, 20.09.git.855483fe5af (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.4
• channels(root): ""
• nixpkgs: /home/cassou/Documents/projects/nixos/system

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[DamienCassou]

In the session running lightdm+i3, I can see:

$ ps aux | grep dbus-daemon
message+  1135  0.0  0.0   7744  4880 ?        Ss   May08   0:03 /nix/store/h3nn2hinxz83zf6yi2fgq9k4dindlvbn-dbus-1.12.16/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
cassou    1913  0.0  0.0   6440  2708 ?        Ss   May08   0:00 /run/current-system/sw/bin/dbus-daemon --syslog --fork --print-pid 5 --print-address 7 --session

$ ps aux | grep dbus-launch
cassou    1912  0.0  0.0   7396  2120 ?        S    May08   0:00 /nix/store/b7d9i2nh42089g5cybac8czv69v7q2gg-dbus-1.12.16-lib/bin/dbus-launch --exit-with-session /nix/store/jvqw2ymbf72yf18q2ly7gxzmykf4s52x-xsession-wrapper /nix/store/s5viq02wwq9bx5692fhpsdxb88v4nfcz-xsession

$ echo $DBUS_SESSION_BUS_ADDRESS
unix:abstract=/tmp/dbus-ENyOScjEok,guid=d0cd18da918d510a34b989a45eb5abb7

In the session running Gnome, I can see:

$ ps aux | grep dbus-daemon
message+  1179  0.0  0.0  10800  6360 ?        Ss   15:52   0:01 /nix/store/h3nn2hinxz83zf6yi2fgq9k4dindlvbn-dbus-1.12.16/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
cassou    1905  0.0  0.0   7264  4640 ?        Ss   15:52   0:00 /nix/store/h3nn2hinxz83zf6yi2fgq9k4dindlvbn-dbus-1.12.16/bin/dbus-daemon --session --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
cassou    2290  0.0  0.0   6224  3532 ?        S    15:52   0:00 /run/current-system/sw/bin/dbus-daemon --config-file=/nix/store/5dnkdk2dr4m52qxpskg84v5xi9in6108-at-spi2-core-2.36.0/share/defaults/at-spi2/accessibility.conf --nofork --print-address 3

$ ps aux | grep dbus-launch

$ echo $DBUS_SESSION_BUS_ADDRESS
unix:path=/run/user/1000/bus

[DamienCassou]

Here is some info about the user's dbus.socket unit:

$ systemctl cat --user dbus.socket
# /nix/store/h3nn2hinxz83zf6yi2fgq9k4dindlvbn-dbus-1.12.16/etc/systemd/user/dbus.socket
[Unit]
Description=D-Bus User Message Bus Socket

[Socket]
ListenStream=%t/bus
ExecStartPost=-/nix/store/zbxfs37qjj6ddrfnzrdnxnkrvvm1ddsf-systemd-245.3/bin/systemctl --user set-environment DBUS_SESSION_BUS_ADDRESS=unix:path=%t/bus

# /nix/store/732vj9z11pby21qc5hnrrwhdcvnixkg7-user-units/dbus.socket.d/overrides.conf
[Unit]

[Socket]

[matthewbauer]

I don't know if it's helpful, but I also get this on SDDM+Plasma5. This on the other hand works:

busctl status org.freedesktop.systemd1