The overlap between package managers and automation frameworks
What do package managers do? Install packages, obviously! But that is not everything. In my opinion, package managers do enough to be characterized as general automation frameworks. For example:
manage configurations and configuration files
manage custom compilation options and flags
provide isolation or containerization
make sure a specific file is present in a specific place given specific conditions
change installation files or configuration based on architecture or other conditions
Not all package managers do all of the above, but you get the idea.
Nix even manages your entire setup with a single configuration file.
It occurred to me that package management could theoretically be managed by an automation framework.
What do I mean by automation framework? Ansible, chef, puppet, or Sparrow.
Now imagine if you were to use one of those package managers as an automation framework. For most of them, it would suck. (nix is a notable exception). So maybe common package managers are just bad automation frameworks?
What if we used an automation framework as a package manager? Well currently, it might also suck, but only because it lacks the package definitions. Maybe it is not a bad experiment to have a distribution managed by a modern automation framework like Sparrow.
What are the benefits?
usable on other distributions
more easily create your own packages on the fly
Greater customization and configurability
use a known programming language that is easy to read to define packages and other functions, instead of a DSL
your package manager can easily automate just about any task using the same syntax and framework
Well you're really feeding my Nix confirmation bias here. I used to use Ansible with my dot files to configure my personal computers to make it easy to get set up on a new machine or server shell account. But it wasn't great because I would have to remember to update my Ansible config whenever I installed stuff with my OS package manager (and usually I did not remember). Then along came Nix and Home Manager which combined package management and configuration management in exactly the way I wanted. Now my config stays in sync because editing it is how I install stuff.
Nix with either Home Manager or NixOps checks all of the benefits you listed, except arguably using a "known" programming language. What are you waiting for?
I am very interested in Nix. The only thing making me hesitate is that it is a bit opinionated. There's a "Nix way of doing things" rather than a general automation framework than can do anything. Am I wrong in thinking this as an outside observer?