SteamOS graphics drivers are suddenly broken

I've got a PC that's had SteamOS installed on it for a while, acting as a Steam media PC, as well as an OwnCloud server and Plex. Suddenly the steam launcher won't start, and complains that I am missing libgl.so.1

Where do I get this? I tried all the top Ubuntu and Debian fixes and I either already have the package installed or it still doesn't fix it. Help?

Type: locate libGL.so

post result

I had to install locate using APT, it wasn't there originally, not sure if that matters.

When I run it I get this:

[email protected]:~# locate libGL.so
/etc/alternatives/glx--libGL.so.1-x86_64-linux-gnu
/etc/alternatives/glx--libGL.so-x86_64-linux-gnu
/etc/alternatives/libGL.so-master
/etc/alternatives/nvidia--libGL.so.1-x86_64-linux-gnu
/usr/lib/i386-linux-gnu/fglrx/fglrx-libGL.so.1.2
/usr/lib/i386-linux-gnu/fglrx/libGL.so.1
/usr/lib/mesa-diverted/i386-linux-gnu/libGL.so.1
/usr/lib/mesa-diverted/i386-linux-gnu/libGL.so.1.2.0
/usr/lib/mesa-diverted/libGL.so-master
/usr/lib/mesa-diverted/x86_64-linux-gnu/libGL.so
/usr/lib/mesa-diverted/x86_64-linux-gnu/libGL.so.1
/usr/lib/mesa-diverted/x86_64-linux-gnu/libGL.so.1.2.0
/usr/lib/x86_64-linux-gnu/fglrx/fglrx-libGL.so.1.2
/usr/lib/x86_64-linux-gnu/fglrx/libGL.so.1
/usr/lib/x86_64-linux-gnu/libGL.so
/usr/lib/x86_64-linux-gnu/libGL.so.1
/usr/lib/x86_64-linux-gnu/nvidia/current/libGL.so.1
/usr/lib/x86_64-linux-gnu/nvidia/current/libGL.so.343.22
/usr/lib/x86_64-linux-gnu/nvidia/libGL.so.1
/var/lib/dpkg/alternatives/libGL.so-master
[email protected]:~#

I created a fresh SteamOS install in Virtualbox on another machine just to compare the two, and I think it has something to do with repositories. I have a repo for Plex Media Server added to mine, plus deb-multimedia.org (forgot what I needed that for but it was something) and also the OpenSUSE OwnCloud repo. I also somehow ended up with http://ftp.us.debian.org/debian/ wheezy main contrib non-free in there, but I don't remember putting that...would that have broken it or conflicted with the normal Valve repos somehow?

Thanks for all your help

I figured out what's wrong. There are a ton of package conflicts because Valve's repos interfered with the other ones I added. I'm just gonna install Linux Mint and call it a day, but thanks for your help! (May be back later if Mint doesn't work haha)

no problem Im on Mint : )

cinnamon is good, check out the settings tab 'general' in there is "disable compositing for fullscreen windows"

now its ok on or off, the weird thing i noticed with cinnamon is you can turn vsync off in game , see your Steam FPS counter at a high fps and not get any tearing.. but if you want to not let the desktop control sync just untick that and let the game do the talking ( i tend to leave it on and turn off vsync in game due to their odly being no tearing, this allows the gpu to run wild and mouse lag to disappear )

Also, from the package manager there are ways to which to install KDE on cinnamon as a login option.