I apologize in advance if this turns out to be a linker problem not related to boost. So here goes: For compatibility/legacy reasons, we can not use the Boost.Build jamfiles to build our application. Accordingly, I've written a set of traditional makefiles to build the project's executables and have run into difficulties. Specifically, when I try to link my test program against the boost test libraries, I get an error message (reformatted for easy reading) saying that the reference to test_main can not be resolved. Here's the spew (formatted to make it easier to read): g++ -g3 -L../long/debug -L/usr/lib -L/usr/local/lib -L/usr/local/lib/stlport -L/usr/local/lib/boost -o "debug/unit_test" debug/longtest.o -lLong -lboost_unit_test_framework-gcc-mt-p -lboost_test_exec_monitor-gcc-mt-p -lpthread -lc /usr/local/lib/boost/libboost_test_exec_monitor-gcc-mt-p.so: undefined reference to `test_main(int, char**)' collect2: ld returned 1 exit status make: *** [debug/unit_test] Error 1 According to nm, the undefined reference, test_main, is defined in the exec_monitor library. I've tried reordering the libraries but no joy. Any advice and/or hints would be very much appreciated. I am using STLPort-4.6.2 and boost_1_32_0 and Linux (I386) Cheers, Michael