Hi, I have not been able to build version 1.31.0. I run bjam -sTOOLS=gcc-nocygwin Basically, I get a lot of undefined references from the linker. The linker cannot find "cpp_main", "init_unit_test_suite", and, so on. It seems to be a problem with the testing, regression testing, unit testing, etc. Greg Silverman Northrop Grumman San Jose, CA