I've successfully been using bumblebee with optirun/primusrun on my Optimus laptop for quite some time now. However, since yesterday, both programs suddenly hang without actually launching anything for about a minute. I did install some regular distribution updates, but none of them appeared to be X related at all. After hanging for a while, both programs exit with an error message:
optirun: [ERROR]Cannot access secondary GPU - error: X unresponsive after 10 seconds - aborting
primus: fatal: Bumblebee daemon reported: error: X unresponsive after 10 seconds - aborting
However, the secondary X server with nvidia driver actually does start up, and when I run, e.g.
DISPLAY=:8 xterm
the xterm window shows up on the external monitor connected to the Nvidia card, so it appears to be a communication problem within bumblebee. Running bumblebeed and optirun with --debug doesn't produce any useful information, both programs just hang for about a minute and then exit.
Any ideas how to fix this?
As usual, I've found the solution myself ~ 5 minutes after posting the question: I had edited my firewall settings, and they were too restrictive - in particular, they prevented bumblebeed from connecting to the X server via port 8001. Firewall settings adjusted, everything back to normal :-/
(Edited the follow up comments back into answer -Editor )
I used
netstat -altupand saw that bumblebeed was inSYN_SENTstate, which usually means that the initial connection was silently dropped by the firewall.