I'll need to look into this. Apparently, FindBoost.cmake solves this by forcing the user to specify the version in find_package(Boost COMPONENTS python27), but the CMake configuration files installed by 1.70 only take find_package(Boost COMPONENTS python), so multiple versions installed at the same time are a problem.

In the meantime, you can add --no-cmake-config to your b2 install command line to skip the installation of CMake configuration files, which ought to give you the 1.69 behavior back.

This is *exactly* the kind of situation I was afraid of when I argued strongly against adding CMake support to my own projects: Before I had to deal with B2 issues that I had difficulties resolving myself. Now I have to deal with B2 *and* CMake issues, being even more dependent on others.

That's not my definition of progress.

-- 

      ...ich hab' noch einen Koffer in Berlin...