at-spi-bus-launcher does not terminate at end of X session

[Daniel Richard G.]

This concerns at-spi2-core 2.36.0-2 in Ubuntu focal.

I log into the Xfce desktop as "skunk" via xrdp, and then logout.

A few minutes later, "loginctl list-sessions" shows the following:

    SESSION UID USER SEAT TTY
          9 0 root
        c10 1000 skunk
         c9 116 lightdm seat0

    3 sessions listed.

Output from "loginctl session-status c10":

    c10 - skunk (1000)
        Since: Fri 2020-05-08 04:03:51 EDT; 6min ago
       Leader: 6009
      Display: :11
      Service: xrdp-sesman; type x11; class user
        State: closing
         Unit: session-c10.scope
        ├─6184 /usr/libexec/at-spi-bus-launcher --launch-immediately
        └─6199 /usr/bin/dbus-daemon --config-file=/usr/share/defaults/at-spi2/accessibility.conf --nofork --print-address 3

These two processes stick around forever until I kill them, or their parent "systemd --user" process. Only then does the session disappear from list-sessions.

When I run "session-status" while I'm logged in, I see a list of about 20 desktop-related processes. All of them except these two go away on logout. These should too.

(Note that this problem does not occur when I log in/out via LightDM on the console.)

[Daniel Richard G. (skunk)]

This bug has LP: 1871726 as a quasi-parent.

Those two processes shown in session-status are deceptive; ps(1) shows a much larger number of processes still remaining from the login session. When the two processes go away, however, all the others follow. The impact of this issue, then, is not limited to a mere two lingering processes.