So I'm running into an embarrassing problem trying to prepare for the computer programming class that I intend to 12-13 year olds in Haskell this coming fall. I had decided to use gloss, an excellent package by Ben Lippmeier that makes it really easy to build images, animations, simulations, and games in a straight-forward and functional way. Excellent... but suddenly broken on my system since installing Ubuntu 11.4, and it looks like the cause traces back to GLUT. Prelude Graphics.Gloss> displayInWindow "Test" (100,100) (100,100) white (Circle 80) freeglut (<interactive>): ERROR: Internal error <Visual with necessary capabilities not found> in function fgOpenWindow X Error of failed request: BadWindow (invalid Window parameter) Major opcode of failed request: 4 (X_DestroyWindow) Resource id in failed request: 0x0 Serial number of failed request: 25 Current serial number in output stream: 28 and Prelude Graphics.UI.GLUT> initialize "foo" [] [] Prelude Graphics.UI.GLUT> get displayModePossible False Nothing I can find to change in GLUT causes displayModePossible to be True, and I'm at the end of my knowledge here. A quick web search turns up the occasional person complaining about the freeglut error, but in all cases they have trouble running any GLUT applications, and it turns out their configuration doesn't do direct rendering. In my case, glxgears and any other non-Haskell GLUT applications I can find work great, but Haskell's GLUT bindings are giving me no hint of success. Any ideas? -- Chris Smith