I'm a newbie to boost, and I'm trying to use boost.thread together with STLport in VC6. When I compile my project in debug version, I get a error message saying "fatal error C1189: #error : 'Build options aren't compatible with pre-built libraries'", the error code is in auto_link.hpp in boost directory: # if (defined(__SGI_STL_PORT) || defined(_STLPORT_VERSION)) && (defined(_STLP_OWN_IOSTREAMS) || defined(__STL_OWN_IOSTREAMS)) # if defined(_DEBUG) && (defined(__STL_DEBUG) || defined(_STLP_DEBUG)) # define BOOST_LIB_RT_OPT "-gdp" # elif defined(_DEBUG) # define BOOST_LIB_RT_OPT "-gdp" # pragma message("warning: STLPort debug versions are built with /D_STLP_DEBUG=1") # error "Build options aren't compatible with pre-built libraries" # else # define BOOST_LIB_RT_OPT "-p" # endif But I don't get this error message in release version. What can I do?