Comment 29 for bug 1758243

@zubozrout: I got the same error (Module 'nvidia' is not found) when I tried it just now. I had to alter the /etc/bumblebee/bumblebee.conf XorgModulePath in 18.10 to get optirun to work with the nvidia 415 driver:

XorgModulePath=/usr/lib/x86_64-linux-gnu/xorg,/usr/lib/xorg/modules,/usr/lib/xorg/modules/input
X

and restart bumblebee (sudo systemctrl restart bumblebeed).

Note that the path used to start with /usr/lib/x86_64-linux-gnu/nvidia/xorg, but it looks like the module now goes just in /usr/lib/x86_64-linux-gnu/xorg:

$ ls /usr/lib/x86_64-linux-gnu/xorg
libglxserver_nvidia.so libglxserver_nvidia.so.415.25 nvidia_drv.so

Not finding bbswitch shouldn't be such a big issue with newer kernals, because the kernel should be able to suspend the card automatically. You could try the latest bumblebee testing PPA (https://launchpad.net/~bumblebee/+archive/ubuntu/testing) and put this line into the [driver-nvidia] section of bumblebee.conf before restarting it:

AlwaysUnloadKernelDriver=true

For more details, see https://github.com/Bumblebee-Project/Bumblebee/issues/978 and specifically https://github.com/Bumblebee-Project/Bumblebee/issues/978#issuecomment-415332707.

There's no cosmic driver in that PPA, but the bionic one works just fine on my cosmic.