Not sure whether this a boost.build problem, a boost.python problem, or simply a failure in my understanding. In boost 1.33.1 one could specify the location of the Python version to be used by Boost.Python using the --with-python-root option to bjam. This isn't working on the RC_1_34_0 branch. (I haven't looked at HEAD.) Looking at the boost root Jamfile.v2, it looks like this is still expected to work, in that there is code that looks for that option and sets some variables based on its value. However, it does not actually work because there is other code in that same file which examines all --with-XXX options to determine which optional libraries to add. So it treats python-root as a candidate for such a library. Unfortunately, it then determines that this isn't a recognized library name, and so errors out. So there seems to be at least some inconsistency here. Also, simply taking out the --with-python-root results in a warning that the Python location was not configured, and so the Boost.Python library won't be built. Is there some other mechanism that one can / is supposed to use to specify this particular bit of configuration information?