Updated my Debian system last night and this moring Xorg wouldn’t work. In /var/log/Xorg.0.log at the end of the file is this:

(II) LoadModule: “nvidia”
(WW) Warning, couldn’t open module nvidia
(II) UnloadModule: “nvidia”
(EE) Failed to load module “nvidia” (module does not exist, 0)
(II) LoadModule: “keyboard”
(II) Loading /usr/lib/xorg/modules/input//keyboard_drv.so
(II) Module keyboard: vendor=”X.Org Foundation”
compiled for 7.1.1, module version = 1.0.0
Module class: X.Org XInput Driver
ABI class: X.Org XInput driver, version 0.6
(II) LoadModule: “mouse”
(II) Loading /usr/lib/xorg/modules/input//mouse_drv.so
(II) Module mouse: vendor=”X.Org Foundation”
compiled for 7.1.1, module version = 1.1.1
Module class: X.Org XInput Driver
ABI class: X.Org XInput driver, version 0.6
(EE) No drivers available.

Fatal server error:
no screens found

Looks like /usr/lib/xorg/modules/drivers/nvidia_drv.so is missing.

Found the fix here:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=420177

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=428580

To create the .so file do the following (as root or using sudo):

cd /usr/lib/xorg/modules/drivers

gcc -shared -o nvidia_drv.so nvidia_drv.o