Scott Lamb! I have the exact same set up as you have and I end up with the same error message as you do. Same as your earlier message: I've downloaded boost-1.30.2 and boost-jam-3.1.7 to my PowerBook running Mac OS X 10.3 (Panther). After installing boost-jam without problems, I'm attempting to build the boost test library as follows: $ uname -a Darwin spiff.local 7.2.0 Darwin Kernel Version 7.2.0: Thu Dec 11 16:20:23 PST 2003; root:xnu/xnu-517.3.7.obj~1/RELEASE_PPC Power Macintosh powerpc $ gcc_select Current default compiler: gcc version 3.3 20030304 (Apple Computer, Inc. build 1495) $ cd boost-1.30.2/libs/test/build $ bjam -sTOOLS=darwin ----- Same errors as you: ...failed darwin-Link-DyLib-action libs/test/build/bin/libboost_prg_exec_monitor.dylib/darwin/debug/ runtime-link-static/shared-linkable-true/ libboost_prg_exec_monitor.dylib... ... ...failed darwin-Link-DyLib-action libs/test/build/bin/libboost_test_exec_monitor.dylib/darwin/debug/ runtime-link-static/shared-linkable-true/ libboost_test_exec_monitor.dylib... ... ...failed darwin-Link-DyLib-action libs/test/build/bin/libboost_unit_test_framework.dylib/darwin/debug/ runtime-link-static/shared-linkable-true/ libboost_unit_test_framework.dylib... ... ...failed updating 6 targets... ...updated 283 targets... Have you or anyone successfully resolved the problem? Thanks. PM