>>> optirun steam

Running Steam on ubuntu 14.04 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(1440016726)
primus: fatal: failed to load any of the libraries: /usr/$LIB/libGL.so.1:/usr/lib/$LIB/libGL.so.1:/usr/$LIB/mesa/libGL.so.1:/usr/lib/$LIB/mesa/libGL.so.1
/usr/$LIB/libGL.so.1: cannot open shared object file: No such file or directory
/usr/lib/$LIB/libGL.so.1: cannot open shared object file: No such file or directory
/usr/$LIB/mesa/libGL.so.1: cannot open shared object file: No such file or directory
/usr/lib/$LIB/mesa/libGL.so.1: cannot open shared object file: No such file or directory
[2015-09-02 18:35:31] Startup - updater built Aug 19 2015 11:27:40