I wrote a simple PoC of a simpler way to achieve something similar:

https://github.com/SirCmpwn/scmake

It's definitely not something you should use, but I hope new things take a similar approach. It's small, give it a read. Here's a somewhat more complicated project that uses it:

https://github.com/SirCmpwn/libccmd

I think from a usability standpoint (both for devs and users) it's really great but the internals could use some work.