In an effort to get OpenGL working on a Dell XPS running 14.04 LTS on Intel graphics hardware, I followed some advice and did the following:
add-apt-repository ppa:oibaf/graphics-drivers apt-get update apt-get upgrade
Now OpenGL works! But the upgrade caused other video problems that make the computer practically unusable. For example, I can no longer run a terminal on the desktop; I can still get a text-mode terminal with ctrl-alt-F1 though.
How can I undo this upgrade? It's the last apt-thing I've done. Alternatively, how do I reinstall the original Dell driver?
More info: I'm pretty sure I'm a victim of this bug, which seems to be unresolved.
The following is info that the very helpful @edwinksl asked for. Too cumbersome for a comment.
jack@hitch:~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.4 LTS Release: 14.04 Codename: trusty jack@hitch:~$ glxinfo | grep -i version server glx version string: 1.4 client glx version string: 1.4 GLX version: 1.4 OpenGL core profile version string: 3.3 (Core Profile) Mesa 10.1.3 OpenGL core profile shading language version string: 3.30 OpenGL version string: 3.0 Mesa 10.1.3 OpenGL shading language version string: 1.30 OpenGL ES profile version string: OpenGL ES 3.0 Mesa 10.1.3 OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.0