flake-utils-plus VS nix-update

You don't need channels to use nix-shell or nix-env. You can generate the Nix path and registry from your flake inputs. flake-utils-plus makes this easy with nix.generateRegistryFromInputs and nix.generateNixPathFromInputs.

Use flake-utils-plus to easily define multiple systems in flake.nix.and then use the --target-host flag of nixos-rebuild to deploy it remotely.

If you're trying to handle multiple systems with one config a flake is a significantly better option. I would personally recommend looking at flake-utils-plus and specifically this example config.

I looked at some past threads / examples and saw people recommend flake-utils-plus, but after reading the examples I don't understand how I would get home-manager on Darwin or Ubuntu.

Depending on your specific needs, the channelsConfig (modify arguments passed to Nixpkgs) and overlay tooling in flake-utils-plus may be adequate: https://github.com/gytis-ivaskevicius/flake-utils-plus/tree/...

For flakes you don't have to set up everything manually there are helper libraries, I use flake-utils-plus.

Converting to flakes is not that hard if you use a good library. The documentation is other people's configs, really.

Neat! I've been using flake-utils-plus's implementation until now. https://github.com/gytis-ivaskevicius/flake-utils-plus/blob/master/lib/repl.nix

I use flake-utils-plus based configuration to apply patches on top of nixpkgs where overlays don't suffice.

You should instead use the regular fetchGit, fetchFromGitHub etc. fetchers in fairly vanilla code, and yes, that often means dealing with checksums in some form. If you truly just want to yeet the latest revision into place no matter what it is, there are ways to automate that still, such as berberman/nvfetcher, or Mic92/nix-update.

Yes, however one downside is that, afaik, the inputs are downloaded eagerly, not lazily. Alternatively there are things like nix-update and nvfetcher.

or https://github.com/Mic92/nix-update

You can also use https://github.com/Mic92/nix-update with a nixpkgs git clone.

I run [nix-update](https://github.com/Mic92/nix-update/) to update stuff. If you want to package something new, first identify the programming language/buildsystem the project is using and than look for a similar project in nixpkgs.