Hello, I'm trying to build GHC from darcs. Unfortunately compilation fails with the following error: ... cpphs: #error Please define LEFTMOST_BIT to be 2^(SIZEOF_HSWORD*8-1) in GHC/Num.lhs at line 27 col 1 make[1]: *** [doc.library.base] Error 1 make[1]: Leaving directory `/home/bas/development/haskell/ghc/libraries' make: *** [stage1] Error 2 ... The following is the part where the error occurs in libraries/base/GHC/Num.lhs : ... #include "MachDeps.h" #if SIZEOF_HSWORD == 4 #define LEFTMOST_BIT 2147483648 #define DIGITS 9 #define BASE 1000000000 #elif SIZEOF_HSWORD == 8 #define LEFTMOST_BIT 9223372036854775808 #define DIGITS 18 #define BASE 1000000000000000000 #else #error Please define LEFTMOST_BIT to be 2^(SIZEOF_HSWORD*8-1) -- DIGITS should be the largest integer such that 10^DIGITS < LEFTMOST_BIT -- BASE should be 10^DIGITS. Note that ^ is not available yet. #endif ... Note that in build.mk I set BuildFlavour = quick and I also tried building it with the following options added: SRC_HC_OPTS += -optc-march=athlon64 -opta-march=athlon64 SRC_CC_OPTS += -march=athlon64 What can be the problem? Thanks, Bas van Dijk Some info on my system (please ask for more if you need it): $ uname -a Linux bassbox 2.6.20-gentoo-r6 #1 PREEMPT Thu Apr 19 10:53:57 CEST 2007 i686 AMD Athlon(tm) 64 Processor 3200+ AuthenticAMD GNU/Linux $ gcc --version gcc (GCC) 4.1.1 (Gentoo 4.1.1-r3)