I have been able to reproduce those missing signals most reliably within a systemd user session (for the system session it works most of the time):
Steps to reproduce missing dbus signals with Ubuntu 16.10 Desktop: Create a ~/.config/systemd/user/terminal.service with this content: [Unit] Description=example unit to open a terminal [Service] Environment=DISPLAY=:0 ExecStart=/usr/bin/xterm SuccessExitStatus=0 15 [Install] WantedBy=default.target Open two terminals. In the first one execute the attached test_systemd_signals.py (which looks for PropertiesChanged Signals): $ python test_systemd_signals.py To see all dbus messages during the test you can run "dbus-monitor --session" in another terminal. In a second terminal start/stop the systemd unit: $ systemctl --user daemon-reload $ systemctl --user start terminal.service $ systemctl --user stop terminal.service With the current systemd package 231-9git1 the test script only shows two status changes (PropertiesChanged signals) sent by systemd: ActiveState: active SubState: running ActiveState: deactivating SubState: stop-sigterm With the patched systemd package the test script should show the last change of the unit status (being set to inactive), too: ActiveState: active SubState: running ActiveState: deactivating SubState: stop-sigterm ActiveState: inactive SubState: dead Ubuntu 16.04 Desktop does not start a systemd user session by default - I created a package (based on https://github.com/joukewitteveen/xlogin) to simplify the process: $ sudo add-apt-repository ppa:seahawk1986-hotmail/xlogin $ sudo apt-get update $ sudo apt-get install xlogin openbox Create a ~/.xinitrc with this content (and make it executable): #!/bin/bash exec openbox-session Then change to a tty console (or use a remote login via ssh): $ sudo systemctl stop lightdm $ sudo systemctl start xlogin@user # replace "user" with an existing user name Now you can open two terminals (a right click on the desktop opens the openbox menu) and follow the steps for Ubuntu 16.10 above. ** Attachment added: "test_systemd_signals.py" https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1632964/+attachment/4762145/+files/test_systemd_signals.py -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1632964 Title: Regression: systemd does not send all queued DBus Signals when a unit gets inactive To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1632964/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs