The best C and [insert any language here] package manager is Nix. Or rather, it should be[1]. I'm fairly confident something like it
will be. If you haven't, please do try it out (or maybe don't[1], but at least read the paper[2] and let its ideas sink in). I honestly just sigh and think "yet another package manager and they still haven't learned..." whenever I see a new one now.
[1]: Unfortunately documentation is famously bad, the repo that holds package declarations is full of undocumented conventions, there often isn't a "blessed" way of doing things, and there are some other warts, such as all the difficulty one may experience from having to learn a new functional, lazy, dynamically typed language. I'm not aware of active, coordinated efforts to improve on these fronts, except for new languages such as Nickel.
[2]: https://edolstra.github.io/pubs/phd-thesis.pdf (don't be discouraged by the number of pages, it's fine if you read just the first part)
[1]: Unfortunately documentation is famously bad, the repo that holds package declarations is full of undocumented conventions, there often isn't a "blessed" way of doing things, and there are some other warts, such as all the difficulty one may experience from having to learn a new functional, lazy, dynamically typed language. I'm not aware of active, coordinated efforts to improve on these fronts, except for new languages such as Nickel.
[2]: https://edolstra.github.io/pubs/phd-thesis.pdf (don't be discouraged by the number of pages, it's fine if you read just the first part)