Folks - I tried this a week ago and it got farther, but the problem is the same: the configure script doesn't look in /usr/local/include for gmp.h etc. And it calls uname with funny options too. Here is the build output: [david@stubb ~/yhc-devel]$ scons scons: Reading SConscript files ... Checking for architecture... x86 Checking for operating system... uname: illegal option -- o usage: uname [-aimnprsv] Checking for Scons binary... "/usr/local/bin/scons" Checking for Scons version... Found version 0.96.1.D001. Checking for Darcs binary... "/usr/local/bin/darcs" Checking for Darcs version... Found version 1.0.5 (release) . Checking for Subversion binary... "/usr/local/bin/svn" Checking for Subversion version... Found version 1.3.0. Checking for GHC binary... "/usr/local/bin/ghc" Checking for GHC version 6.4.1 or later... Found version 6.4.1. Checking for C header file gmp.h... no Error. libgmp must be installed and gmp.h made accessible before you can compile Yhc. [david@stubb ~/yhc-devel]$ locate gmp.h /home/david/Haskell/ghc-6.4.1/ghc/includes/gmp.h /home/david/Haskell/ghc-6.4.1/ghc/rts/gmp/gmp.h /home/david/yhc-devel/_darcs/current/src/runtime/BCKernel/msvc/gmp/gmp.h /home/david/yhc-devel/src/runtime/BCKernel/msvc/gmp/gmp.h /usr/include/netinet/igmp.h /usr/local/include/gmp.h /usr/local/lib/ghc-6.4.1/include/gmp.h /usr/obj/usr/src/tmp/usr/include/netinet/igmp.h /usr/src/sys/netinet/igmp.h Cheers, - David -- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man. -- George Bernard Shaw