Troubleshooting

Failed to connect to user scope bus via local transport

User environment variables required for systemd user configuration are not present. This typically happens with SSH and sudo commands.

Failed to connect to user scope bus via local transport:
$DBUS_SESSION_BUS_ADDRESS and $XDG_RUNTIME_DIR not defined (consider using
--machine=<user>@.host --user to connect to bus of other user)

# Export required user systemd unit environment variables.
export XDG_RUNTIME_DIR="/run/user/$(id -u)"
export DBUS_SESSION_BUS_ADDRESS="unix:path=${XDG_RUNTIME_DIR}/bus"

# Enable service lingering for user.
loginctl enable-linger {USER}

Setup Systemd User Environment to prevent errors in the future.

Re-run command.