Closed MichaIng closed 4 years ago
I learned that there is no interest in native LXDE support and that the LXDE packages from archive.raspberrypi.org are highly modified on different layers (LXDE-pi
session with no lxappearance support at all but own appearance tool), but hopefully someone has still an idea what the issue can be here.
I tried to replicate on Raspberry Pi OS 32-bit with desktop and on regular RPi desktop as well as when manually switching session profile from LXDE-pi to LXDE, lxappearance
starts, even that on LXDE-pi session its switches have no effect and chosen icon set/theme etc are not applied or selection saved.
What I see as error message:
** (lxappearance:1350): WARNING **: 19:07:57.543: lxappearance.c:67: Failed to connect to the session message bus: Failed to connect to socket /run/user/0/bus: Connection refused
The exact same shows up when installing lxde
on Raspberry Pi OS Lite AFTER killing dbus-launch
, so that it hangs is a difference an I try to figure out which package or config makes the difference and why on regular Debian (any other SBC or machine) this issue does not exist.
Another day of testing and debugging and finally I found a solution for hanging lxappearance
on TigerVNC LXDE sessions. Don't ask me for details why this is required in this specific circumstance, but apt install dbus-user-session solves the issue.
dbus-daemon
+ dbus-launch
instance is started with a specific ID. On lxappearance
start, the exact same dbus-launch
(same cmd options, same ID) is attempted to be started again, which hangs. Only a single instance is allowed, which is somewhat explained in the package details.dbus-daemon
instance is started a systemd --user
child process, the dbus-launch
is not visible. This seems to allow the concurrent dbus-launch
instance(s) then.Here the different process hierarchy can be seen:
If someone has some deeper insights why this is required for lxappearance
within TigerVNC LXDE session only, while in no other case a similar issue was observed, I would be very interested.
When I find time, I do some investigation what RealVNC virtual desktops do differently so that it is not an issue there, but for today I'm happy to have found a solution and mark this issue hence as closed.
I'm not sure which component of the RPi repository makes the difference compared to Debian, so I'm reporting the following issue here:
When installing TigerVNC and LXDE on RPi with the RPi repository applied, starting LXAppearance within a VNC LXDE session hangs the whole desktop. The mouse pointer gets a loading circle, no LXAppearance appears and any desktop interaction is frozen, aside of moving the mouse cursor.
Checking processes on a second session reveals that it hangs on
dbus-launch
and killing thisdbus-launch
child makes LXAppearance appear and function normally, no further issues until it is opened again:This does not happen on any other SBC or PC with Debian, not tested on RPi 64-bit OS on my end. It only happens within virtual TigerVNC desktop sessions, not RealVNC, nor local desktop.
Neither TigerVNC nor LXDE session logs show anything related, but I can of course provide logs and info if required, but I suggest to simply try to replicate on a fresh Raspberry Pi OS 32-bit Lite with the above two packages installed an simply use default setup/configs, no modifications. I think TigerVNC will invoke LXDE automatically, but in case, this is how I do currently (was playing around much, all without any effect on the issue):
cat /root/.vnc/xstartup
tigervncserver :1 -verbose