https://bugs.freedesktop.org/show_bug.cgi?id=29066
--- Comment #12 from Marek Olšák maraeo@gmail.com 2010-07-27 03:43:29 PDT --- It doesn't install anything, so there is nothing to revert. Your system will be untouched.
LIBGL_DRIVERS_PATH=some_path program
says that the 3D driver for the "program" is loaded from "some_path".
If you don't type "LIBGL_DRIVERS_PATH=some_path", the driver will be loaded from your default system location.