Hi all, I'm trying to install the easyVision library on OS X, following the notes at http://mit.edu/harold/Public/easyVisionNotes.html. However, despite a few hours web trawling and hacking away with various cabal options, I can't get "hmatrix" to install. I'm using OS X 10.5.8 with GHC 6.10.4. I installed gsl using macports, as suggested in the notes above, but cabal doesn't seem to be able to find it. The error I'm getting is: [13:22:35 dmorti hmatrix-0.8.2.0]$ cabal install hmatrix Resolving dependencies... [1 of 1] Compiling Main ( /var/folders/05/05Ltg9vxE+a1hR422nbuE++++TI/-Tmp-/hmatrix-0.8.2.05810/hmatrix-0.8.2.0/Setup.lhs, /var/folders/05/05Ltg9vxE+a1hR422nbuE++++TI/-Tmp-/hmatrix-0.8.2.05810/hmatrix-0.8.2.0/dist/setup/Main.o ) Linking /var/folders/05/05Ltg9vxE+a1hR422nbuE++++TI/-Tmp-/hmatrix-0.8.2.05810/hmatrix-0.8.2.0/dist/setup/setup ... Configuring hmatrix-0.8.2.0... Checking foreign libraries... FAIL *** Sorry, I can't link GSL. *** Please make sure that the appropriate -dev packages are installed. *** You can also specify the required libraries using *** cabal install hmatrix --configure-option=link:lib1,lib2,lib3,etc. setup: Package hmatrix-0.8.2.0 can't be built on this system. cabal: Error: some packages failed to install: hmatrix-0.8.2.0 failed during the building phase. The exception was: exit: ExitFailure 1 It appears that others have also had this error, but have been able to fix it up by including "--extra-lib-dirs" and "--extra-include-dirs" options, or using "ld-options: -framework vecLib". I've tried both of these approaches, but still get the same errors. Can anyone offer any suggestions? Thanks very much for your help, Duncan Mortimer