Don't just vendor - rebuild the ecosystem and persuade the vendor to work on software management ...

Because they don't wear the same rose-tinted glasses as you? Because in their world view this particular problem just doesn't exist? (After all, isn't that one of the selling points of Rust - whole classes of major problems in C just disappear because the concept doesn't make sense in the Rust world.)

It's like a bird trying to explain to a fish how you spread your wings to soar in the wind - the fish (one or two excepted) will have no idea what you're talking about.

Cheers,
Wol

Just because Rust chose different solutions than you prefer for the problem of backward compatibility, doesn't mean that they don't care.
Just because somebody else does something different from what you think would be the correct solution doesn't mean they are doing it wrong. It's quite possible that you are wrong. Not everybody except you is an idiot. Do you get that?

If you think backwards compatibility in the C ecosystem is so far superior, then where are C Editions? Where is the common practice in the C community to use Semantic Versioning?
These things work _really_ well in the Rust ecosystem. And they are either completely absent (Editions) or used extremely rarely (SV) in C.

Except from very few examples like glibc there are few projects in the C community that really care about backward compatibility to the extent possible with Rust Editions and Semantic Versioning. Most projects are stable because they are not changed much on the interface level anymore. glibc being a notable exception.