On Wed, Jul 28, 2010 at 11:10 AM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > You are passing the CFLAGS="-arch i386" to C but not g++ hence g++ is using the 64 bit. You need to set CXXFLAGS also to use 32 bit. yes, but why would it not be able to find any CXX compiler when setting those flags?