I think language-specific package managers are just fine for sharing source code for that language with other developers of that language. But as soon as you need to do more than that they become extremely problematic. The dependency tree for a Crate (or a package in any other similar system) ends where the Rust dependencies end. It cannot describe the full dependency graph for any package that depends on a program or library written in another language. I'm more familiar with Ruby so here's a real-life example: The mysql2 gem needs to compile a C extension and link against libmysqlclient. However, the 'gem' utility only handles Ruby dependencies, so in order to 'gem install mysql2' you need to use your system package manager to provide 'libmysqlclient'. There's always going to be this disconnect and you'll have to use multiple package managers in order to get anything working. It's very error prone. Wouldn't be great if a single packager manager could describe the complete dependency graph? This is a big reason why I advocate for GNU Guix. I do devops for a living, and much of the difficulties I face are due to problems trying to glue multiple package managers together.

Not your parent, but I personally believe that using "package managers" to describe both of these things conflates the issue. That is, both are valuable, for different reasons. The shortest way that I can describe it is this: I use my system package manager to install things for software that I'm not developing, but language-specific managers for software that I am actively developing. When I used to write a lot of Ruby, I had my own install, but now that I mostly write Rust, I have Ruby installed via apt-get.

The two styles of managers just have different goals. That is, a package manager such as apt has the goal of creating a single, harmonious system from stuff written in many languages. But a language-specific package manager like Cargo has the opposite goal: to provide a good way of writing software written in one language across multiple systems. This is where most of the tension comes from. The rest of it is from the same general structure, but with different specifics: the goals of these kinds of systems are very different, and conflicting.

Software is hard.

There's no need for two styles of package managers. GNU Guix and Nix can serve both purposes (and more) very well, for example.

I think language-specific package managers are fine for easily sharing source code amongst developers using the same language, but they shouldn't be used in a production system.

I don't necessarily disagree. I think your third sentence still implies two styles, which is contradicting your first.

Nix and Guix don't work on Windows, right? They're still not close to a solution until they do.

If you're on Windows, then fine use whatever is available. A language specific package manager is about as good as it gets there. There are no good package managers for Windows, and I don't think there can be. I don't even know if you can isolate builds in a container like you can on GNU/Linux. That's a crucial OS feature. Besides, I aim to liberate users, not enslave them, so I develop for the GNU system, not Windows.

The third sentence is not a contradiction. I'm just saying that I can live with people using language-specific package managers, but really they would be better off with a general-purpose one.

There are several package managers for Windows:

https://en.wikipedia.org/wiki/List_of_software_package_manag...