xmkmf 
make 'CC=gcc -arch ppc -arch i386 -I/Developer/SDKs/MacOSX10.4u.sdk/usr/X11R6/include -L/Developer/SDKs/MacOSX10.4u.sdk/usr/X11R6/lib -iwithsysroot /Developer/SDKs/MacOSX10.4u.sdk -isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4'