- If you have to use a `make' that does not support the `VPATH'
-variable, you have to compile the package for one architecture at a
-time in the source code directory. After you have installed the
-package for one architecture, use `make distclean' before reconfiguring
-for another architecture.
+ With a non-GNU `make', it is safer to compile the package for one
+architecture at a time in the source code directory. After you have
+installed the package for one architecture, use `make distclean' before
+reconfiguring for another architecture.
+
+ On MacOS X 10.5 and later systems, you can create libraries and
+executables that work on multiple system types--known as "fat" or
+"universal" binaries--by specifying multiple `-arch' options to the
+compiler but only a single `-arch' option to the preprocessor. Like
+this:
+
+ ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
+ CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
+ CPP="gcc -E" CXXCPP="g++ -E"
+
+ This is not guaranteed to produce working output in all cases, you
+may have to build one architecture at a time and combine the results
+using the `lipo' tool if you have problems.