> For the big majority of projects out there, it seems to me that it is perfectly fine to handle that manually, because projects are not that big. Do we agree o

> For the big majority of projects out there, it seems to me that it is perfectly fine to handle that manually, because projects are not that big. Do we agree on that? Let's also agree that every time you change a .cpp file you compile it, and every time you change a .h file you compile all the affected .cpp files. No we don't agree on that. That is the entire point of having a build system. Even proto files you gave as an example, may import other proto files. When you change one of the imported files you have to recompile all proto files that import that file, transitively. I have, unfortunately, worked with build systems that do not capture all dependencies and systems that capture way too many dependencies. The former resulted in many hours spent debugging non existent problems, and the latter resulted in many hours spent waiting for compilation to finish.