One should be able to test a sandbox library within its own sandbox directory. I think it is a fault of the Boost Build system that it does not automatically place the compiler include flag for the sandbox library before the compiler include flag for a Boost distribution when executing the compiler's command line and BOOST_ROOT ( or BOOST ) points to a Boost distribution.
I have not been able to run msvc tests because of link problem. However it seems that this user-config.jam solves the issue of reverse order of include path. Can you try, replacing paths with your installation paths of course? Maybe you do not need the first compileflag. using msvc : 10.0 : : <compileflags>"\"-ID:\\Softs\\Microsoft Visual Studio 10.0\\VC\\include\"" <compileflags>"\"-ID:\\sandbox\\type_traits\"" <compileflags>"\"-ID:\\Softs\\1.5\\mgw-release\\boost\\include\"" ; msvc is so much complicated than g++. I have already spent hours trying to make it work. Is there anybody able to run the tests with msvc? Frédéric