X windows broken after upgrade

[AN]

Hi:

I just updated another box a few minutes ago and after rebooting startx 
does not work.  At r343589 X is now broken, the error I receive is:

(EE)
Fatal server error:
(EE) Cannot run in framebuffer mode. Please specify busIDs  for all 
framebuffer devices

I tried rebuilding mesa and Xorg server but it did not help.

Nothing in the log seems obvious, any help would be really appreciated.

Thanks in advance.