How to build a project with cmake along with a third party library?

Question

CMake

There is my project and there is a third-party lib from github with its own CMakeLists. I added this CMakelists via

add_subdirectory

but how do i run

make

to get lib.a and add it to the project?

Answer 1

What for?
If you link with her, then just call her by name. Inclusion via add_subdirectory implies that all links and dependencies are monitored by cmake. You just write target_link_libraries for your project with this either.
If "just collect" - then there is no need to turn it on at all. Instead of make, it is now customary to run cmake --build (because besides make there are all sorts of ninja and msbuild)