> Do you actually have the X11 development files installed? > If so, what did 'runhaskell Setup.hs configure' say? Sorry for not being clear earlier, but I thought, I was actually trying to install these X11 development files you mention: I first did: ~/xmonad-0.2 <45> runhaskell Setup.lhs configure --prefix=$HOME Configuring xmonad-0.2... configure: /apps/free/ghc/6.6/bin/ghc-pkg configure: Dependency base>=1.0: using base-2.0 Setup.lhs: cannot satisfy dependency X11>=1.2.1 Then, I downloaded the X11-1.2.2 package and that's when I get the link error. Here's the entire transcript: Please let me know if this is what you asked. -Madhu ~/X11-1.2.2 <51> runhaskell Setup.hs configure --prefix=$HOME Configuring X11-1.2.2... configure: /apps/free/ghc/6.6/bin/ghc-pkg configure: Dependency base-any: using base-2.0 configure: Using install prefix: /user/a0875389 configure: Binaries installed in: /user/a0875389/bin configure: Libraries installed in: /user/a0875389/lib/X11-1.2.2/ghc-6.6.20070213 configure: Private binaries installed in: /user/a0875389/libexec configure: Data files installed in: /user/a0875389/share/X11-1.2.2 configure: Using compiler: /apps/free/ghc/6.6/bin/ghc configure: Compiler flavor: GHC configure: Compiler version: 6.6.20070213 configure: Using package tool: /apps/free/ghc/6.6/bin/ghc-pkg configure: Using ar found on system at: /usr/bin/ar configure: No haddock found configure: No pfesetup found configure: Using ranlib found on system at: /usr/bin/ranlib configure: Using runghc found on system at: /apps/free/ghc/6.6/bin/runghc configure: No runhugs found configure: No happy found configure: No alex found configure: Using hsc2hs: /apps/free/ghc/6.6/bin/hsc2hs configure: No c2hs found configure: No cpphs found configure: No greencard found checking for gcc... gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking how to run the C preprocessor... gcc -E checking for X... libraries /usr/X11R6/lib, headers /usr/X11R6/include checking whether -R must be followed by a space... neither works checking for gethostbyname... yes checking for connect... yes checking for remove... yes checking for shmat... yes checking for IceConnectionNumber in -lICE... yes configure: creating ./config.status config.status: creating config.mk config.status: creating X11.buildinfo config.status: creating include/HsX11Config.h config.status: include/HsX11Config.h is unchanged ~/X11-1.2.2 <52> runhaskell Setup.hs build Preprocessing library X11-1.2.2... /usr/bin/ld: cannot find -lX11 collect2: ld returned 1 exit status linking Graphics/X11/Types_hsc_make.o failed command was: ghc -lX11 Graphics/X11/Types_hsc_make.o -o Graphics/X11/Types_hsc_make Setup.hs: got error code while preprocessing: Graphics.X11.Types