I'm not sure how to debug this. I don't see anything obvious in `.xsession-errors` so any advice is welcome. I'll just describe the behaviour I'm observing with: > xfce4-power-manager-1.6.0-5.fc26.x86_64 One issue is that I can't move display brightness with the slider when I right click on the tray icon. As soon as I click the slider, the pop-up closes. Another issue is that very often, mouse over or right-click over the applet icon does nothing. If I right click and then wait long enough without clicking anywhere else, the pop-up appears. When working on batteries display switches brightness sometimes randomly. I'm thinking the power manager is freezing for some time and then applet and power manager settings need to wait long before they can get any interaction with the power manager. I'm not sure all of the above is one bug or multiple. I'm just lost as to how to start with this, so decided to file a bug anyway to hopefully get more information about debugging these.
Now I disabled nvidia/nouveau completely, I am able to move audio and display brightness sliders properly. This is how I did: * add `rd.driver.blacklist=nouveau` to /etc/default/grub kernel command line options * rebuild grub config * add `blacklist nouveau` to /etc/modprobe.d/00local.conf
That is unfortunate, not sure how we can prevent or "know", if a driver doesn't work correctly with the kernel (I don't suppose there is any reasonable method, also because it's not just a driver, but a specific version combined with a specific type of hardware...). I'd personally close this as INVALID or WONTFIX unless you see any benefit in keeping this bugreport open.
I personally don't care much more about the bug but people that want to use nvidia card might be. The interesting thing is what causes some applets behave in a bad way while firefox, gimp and all other normal programs I've used, are performing nicely. IMO there are things to be fixed if somebody has the time to work on them and tell me what debug information I can provide. Otherwise I'm ok for the bug to be closed.
You can try to recompile the power manager in debug mode, then attach the power manager panel plugin to gdb to reproduce the crash. It is definitely a misbehaving driver, but might hide behind a bug in the applet.
Actually I could reproduce the issue while nouveau is disabled. Probably just less obvious. On the other hand I can't reliably reproduce. I'll be updating to Fedora 27 hopefully during the weekend and will check how the new version behaves. I can try debug build if issue still persists. Thanks.
No more updates in a while, closing as per comment 2