If—instead of letting Boost.Build construct and link with the right libraries automatically—you choose to use a pre-built Boost.Python library, you'll need to think about which one to link with. The Boost.Python binary comes in both static and dynamic flavors. Take care to choose the right flavor for your application. 
The dynamic library is the safest and most-versatile choice:
It might be appropriate to use the static Boost.Python library in any of the following cases:
 Because of the way most *nix platforms share symbols among dynamically-loaded objects, I'm not certain that extension modules built with different compiler toolsets will always use different copies of the Boost.Python library when loaded into the same Python instance. Not using different libraries could be a good thing if the compilers have compatible ABIs, because extension modules built with the two libraries would be interoperable. Otherwise, it could spell disaster, since an extension module and the Boost.Python library would have different ideas of such things as class layout. I would appreciate someone doing the experiment to find out what happens.