Features aren't just checkboxes. It's about the whole package and how they make everything work together.

I need a language with minimal runtime, good support for the C ABI and structure formats, decent macros, good ecosystem and community for mainstream programming needs, and support for async.

Where else can I find that whole package?

Go has too much of a runtime, GC, and doesn't support C structure formats very well (i.e. best case you need to copy/translate them to Go; you can't operate on them directly).

C++ can do it, but the details are ugly and the result unsatisfying.

Ada lacks macros and a mainstream ecosystem.

So... what do I use if not rust?