Comment 16 for bug 1257434

I need to investigate this further but it looks like a bug in the driver package (the nvidia-331-prime alternative was not removed).

If you want to go back to a fully working system, you should do the following:

1) sudo update-alternatives --config x86_64-linux-gnu_gl_conf
2) Select the alternative that contains the word "mesa".
3) type:
sudo ldconfig
sudo update-initramfs -u

You might want to repeat the steps to fix the alternative for i386:
1) sudo update-alternatives --config i386-linux-gnu_gl_conf
Steps 2 and 3 are the same.