- CMake 3.9: required by Nowide, I'm not sure why. Also, required for FindMPI to define an imported target. Building Boost.MPI is optional though. I use find_dependency there which requires 3.9. - CMake 3.13: required for Boost installation support.
- CMake 3.14: required for FindPython to be modern enough to make building Boost.Python reasonably easy. (Building Boost.Python is optional, though.)
There are also less important nice-to-have things such as
- CMake 3.10: adds include_guard() - CMake 3.12: adds CONFIGURE_DEPENDS to file(GLOB - CMake 3.15: adds VERBOSE/DEBUG to message(
Opinions?
Given that using CMake for Boost is optional itself, I'd go for 3.13 at least (based on Andreys list of OS cmakes) and would even suggest 3.14. Having Boost.CMake work well is IMO more important than supporting users who want to install Boost with CMake and insist on using the OS cmake. Especially as this is a long-term thing, so distros might already upgrade in the meantime and that installing cmake is reasonably easy.