compiling C++ with the scons compiler

[anibio]

I am using Mac OS X 10.8.2 and I am compiling my code using the scons compiler.
I am using the 32 bit xerces-c database version 2.8.0.

when I am trying to build I get errors:

scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
...
ld: warning: ignoring file /usr/xerces-c_2_8_0-x86-macosx-gcc_4_0/lib/libxerces-c.dylib, file was built for unsupported file format ( 0xce 0xfa 0xed 0xfe 0x 7 0x 0 0x 0 0x 0 0x 3 0x 0 0x 0 0x 0 0x 6 0x 0 0x 0 0x 0 ) which is not the architecture being linked (x86_64): /usr/xerces-c_2_8_0-x86-macosx-gcc_4_0/lib/libxerces-c.dylib
...
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
scons: *** [wntevo] Error 1
scons: building terminated because of errors.

I checked my libxerces-c.28.0.dylib file:

$file libxerces-c.28.0.dylib
libxerces-c.28.0.dylib: Mach-O dynamically linked shared library i386

What should I add to my SConstruct file to make it build in i386 on a x86_64 machine?

[fafner]

Wouldn't it be easier to install a 64-bit version of libxerces?