[saurik]

They clearly do manage "dependency versions" (that's what they do: that's the primary purpose of say, apt). As for the other things, I am pretty certain those are anti-features? I don't want the way I find and manage libraries and depenendencies to assume I am going to use some specific build environment, and the entire point of good package management is to be able to reuse packages so encouraging developers to "control how dependencies are built" is asking for trouble.

[Rusky]

System-wide package managers give you a single, global version of a package built to interact solely with the rest of that one distribution.

I absolutely do want to control how dependencies are built- I want to build them in debug mode, link them using LTO, cross-compile them, or (Rust-specific, since someone mentioned Cargo) switch the panic strategy. Further, many packages I depend on via language-specific tools likely will never be in any distro's repository, nor should they be.

As for assuming a build environment, that may be an issue with a language like C or C++ that has already gone a different route, but it's better when a language has a single, established way of building things that a package manager can integrate with.