This might be an unpopular opinion, but compiling a program into a local directory shouldn't try to install packages globally. `make install`, I could understand doing that.
I had no idea that cmake would do this, after reading quite a lot of things about cmake v.s. make and how to write various makefiles for them. I posit that the C build tools are fundamentally hard to comprehend.
If you embed the source in your project, the terribleness is about adding to your Makefile: