Yeah I think it points to a culture problem. In some ways because dependency management is so easy with Cargo, I think it creates the temptation to just throw in some dependencies to make something work without truly understanding the overall complexity of what you're creating. Something very similar happens in the NodeJS world.
> it splits the ecosystem
This is something I've really noticed with Rust: it almost seems like there are really two things: Rust, and Rust+Tokio. I'm a bit ambivalent about Tokio being baked into so many libraries: I think it's great to have as an option, but once I decide to use one library built around Tokio, it imposes a lot of constraints about how the flow of control is going to work in my program.
A lot of what is not enjoyable about rust as a user is really nice when it's being imposed on people who are not you, whose work you're interfacing with.
If we all have the attitude "it's good/fast because it's rust" this is not going to lead to a lot of cruft making its way into the ecosystem.
Obviously, in the real world, this basically never happens. Performance is one thing that's basically always going to 'leak', so you still get people rewriting stuff in assembly, or making custom asics, because the abstractions that higher level languages offer are not perfect.
In a strongly typed language, with strong safety guarantees, I think there are less ways an abstraction can leak (for instance, by corrupting memory or whatever), so there's a correspondingly lower cost to pulling in a dependency than there would be if you were working in an unsafe language, or a dynamic one.
I also think if performance is the only way in which your dependency leaks implementation details, then it still makes sense to pull in a dependency first, profile, then swap out if necessary.
We absolutely have an NPM/leftpad culture in Rust.
Is that better or worse than C and C++ where dependencies are so painful that you end up reinventing the wheel most of the time? I honestly don't know.
On UNIX systems just using pkg-config and similar tools, or just adopt either conan or vcpkg, which contrary to cargo also support binary libraries out of the box.
Plus vendoring C and C++ libraries is not a dark science, only known by old druids.
Also with c/c++ style system dependencies, I feel like there are a lot of issues with things like version conflicts which are solved much more simply by a package manager like cargo.
I agree that it's functional, but to say relatively easy I think is a bit of a stretch.
Usually when compiling from source many libraries provide pkg-config configuration files on "make install".
Right now, I'm using the latest version of "reqwest" known to "crates.io." It's pulling in Tokio v0.2.23, not the new tokio v1.0.0. No surprise there, the new version only came out yesterday. So we'll see how the new version works at some time in the future.
It's good to get to version 1. The semantic versioning rules allow breaking changes without changing the first digit when the first digit is 0. Typical complaint on forums: "bignum happens to use rand internally, and it happens to only use version 0.5.0, with restrictions against using a higher version due to breaking changes." Rust still has many low-level crates at version 0.x.x, from "bytes" to "uuid". Reaching 1 indicates greater stability.
Rust makes version pinning feasible, e.g. by allowing multiple versions of the same package in a build (not all module systems have this feature!) but doesn't encourage it. You've identified a problem with using 0.x.y-versioned packages as dependencies (which means de-facto opting out of semver), but that's not a problem with Rust specifically; it could occur in any language.
It is up to the library authors to uphold its semantics.
Isn't it the case with pkg-config that everything is stored in a central location?
In any case, I think you can't seriously argue that the c/c++ dependency management solution is anywhere close to running `cargo build`/`cargo run` in terms of simplicity.
Specially the C++ community has seen lack of something like cargo as weaknesses and moved to sort it out.
That split between "sync" and "async" was always there, for networking libraries. E.g. on C/C++ you find libs that run on libevent, or Boost.Asio, or other varieties, and they don't mix, so you end up spawning a seperate thread - exactly the same thing.
And this is, IMHO, how we should see Tokio + async: as a more ergonomic libevent.