LO needs to build both against MacOSX SDK and not produce universal binaries. diff -ru python3.old_/configure python3/configure --- python3.old_/configure 2012-09-29 10:00:50.000000000 +0200 +++ python3/configure 2012-11-13 16:37:26.030013256 +0100 @@ -6353,7 +6353,19 @@ if test "${enable_universalsdk}"; then UNIVERSAL_ARCH_FLAGS="" if test "$UNIVERSAL_ARCHS" = "32-bit" ; then - UNIVERSAL_ARCH_FLAGS="-arch ppc -arch i386" + # LO does not use Universal Binaries (but the only way to set a SDK + # here implies that, so de-universalize here...) + case `/usr/bin/arch` in + i386) + UNIVERSAL_ARCH_FLAGS="-arch i386" + ;; + ppc) + UNIVERSAL_ARCH_FLAGS="-arch ppc" + ;; + *) + as_fn_error $? "Unexpected output of 'arch' on OSX" "$LINENO" 5 + ;; + esac ARCH_RUN_32BIT="" LIPO_32BIT_FLAGS="" elif test "$UNIVERSAL_ARCHS" = "64-bit" ; then