I would like to share about a very annoying bug that pestered me a lot. I always wondered what it was. It was difficult to me to trace it because I'm not a programmer.
I'm using Slack64-current, or 14.0 RC5 as it is now. I'm also using AlienBob's KDE 4.9.1 packages, which work really well.
Since I use a laptop, I tend to use the suspend to Ram feature fairly frequently. During these sessions, and as the uptime grows, sometimes certain apps refuse to start.
An examination of current processes show that old apps that you thought you exited, were still running, but with no GUI. The app you recently started is also there, but with the GUI not showing.
Starting the app with strace shows that the app hangs expecting a connection to /tmp/fam-$USER.
Killing the app and restarting it does not work. Many times, in frustration, I had to reboot.
As it turned out, this wasn't necessary. Killing the gam_server process usually restored things to normality.
So, if you have been bitten by this bug, please take notice!
Here are two nice links talking about this bug:
"Deadlock in FAM/KDirWatch usage"
"gam_server deadlocks, leading to all KDE applications hanging at start"