After upgrading OpenGL, I tried to re-install FieldTrip 0.2.4 and encountered these errors, from GHC 6.10.1 on Fedora 10 Linux: [ 3 of 17] Compiling Graphics.FieldTrip.Vector2 ( src/Graphics/FieldTrip/Vector2.hs, dist/build/Graphics/FieldTrip/Vector2.o ) src/Graphics/FieldTrip/Vector2.hs:69:9: Duplicate instance declarations: instance Functor Vector2 -- Defined at src/Graphics/FieldTrip/Vector2.hs:69:9-23 instance Functor Vector2 -- Defined in OpenGL-2.2.3.0:Graphics.Rendering.OpenGL.GL.Tensor src/Graphics/FieldTrip/Vector2.hs:72:9: Duplicate instance declarations: instance Applicative Vector2 -- Defined at src/Graphics/FieldTrip/Vector2.hs:72:9-27 instance Applicative Vector2 -- Defined in OpenGL-2.2.3.0:Graphics.Rendering.OpenGL.GL.Tensor [root@squirrel]# ------------ Previously, I had installed FieldTrip 0.2.4 with earlier versions of OpenGL. I got some scary-looking warnings in the 'configure' step: Configure warns: Warning: This package indirectly depends on multiple versions of the same package. This is highly likely to cause a compile failure. package graphicsFormats-0.1 requires OpenGL-2.2.1.1 package GLUT-2.1.2.1 requires OpenGL-2.2.2.0 package FieldTrip-0.2.4 requires OpenGL-2.2.2.0 -- but I did have both those versions of OpenGL installed at the time, and it did work. Is my best move now to re-install OpenGL 2.2.1.1 and OpenGL 2.2.2.0, keeping OpenGL 2.2.3.0, or had I better remove the newest version of OpenGL and just keep the older two? I hope I'm not answering my own question here, in my previous post, about the desirability of moving FieldTrip away OpenGL -- however, I think people meant something more than version problems by that ;-) -- ___ ___ __ _ / _ \ / _ \| | | | Gregory D. Weber, Associate Professor / /_\// / | | | /\ | | Indiana University East / /_\\/ /__| | |/ \| | http://mypage.iu.edu/~gdweber/ \____/\_____/\___/\__/ Tel. (765) 973-8420; FAX (765) 973-8550