This is not what IDE support means for the most part. The big question is does the IDE understand how the files are compiled well enough for its autocompletion and jump-to-definition features to work. A build system/IDE combo which does not support this is DOA to most users. Sadly, there is no standardisation of the interface between IDEs, build systems, and compilers (though the language server spec from Microsoft is making some headway in this regard), so each of these integrations needs to be rebuilt each time, making development of new build systems extra painful.