Make sure that the schema is valid by running it through some program. Does the Nix CLI provide a way to validate the schema?

What policy should we adopt for inclusion in the flake registry?

Should we allow any references that are getting submitted? Or do we have some criteria for inclusion?

Some facts:

• The registry is a global namespace and will hit naming collisions at some point
• The registry is not strictly necessary. It's mainly a shorthand notation.

This issue was triggered by #24. It seems to be just a normal tool, not specific to Nix.

Once we agree I will create a README and add the policy to it

The idea of flakes is to also replace channels. In a flake, one can choose what nixpkgs url to use. When not working with a local flake, one can invoke e.g.

nix shell nixpkgs#hello

If one wants a version from 20.09, one needs to use

$ nix shell nixpkgs#hello --override-input nixpkgs github:nixos/nixpkgs/nixos-20.09

It would be convenient if there would be registry entries for all stable versions so one could write

nix shell nixos-20.09#hello

We do need to draw a line here because we can't add all branches of whatever project. Also, it's not bad having to learn to use override-input. And, it prevents users from relying specifically on nixos-20.09 in a flake.nix where maybe they should not.

I do not know whether we should add the stable versions or not, but I can imagine here the convenience outweighs the disadvantages.

points to current stable nixos release. I am unsure if registry allows ref.
I also proposed for branch which would make this easier NixOS/nixpkgs#266149

What are the rules for all this? Which flakes can be added here anyways?

I'd love to see flake-utils added here because basically everyone uses it https://github.com/search?q=flake-utils+extension%3Anix&type=code

@numtide thoughts?

The nixpkgs entry right now is github:NixOS/nixpkgs. This means that a reference to the nixpkgs flake will default to the master branch, meaning anyone who uses this may get packages that haven't yet been built by hydra. This is surprising and something of a footgun.

The registry should instead set it to github:NixOS/nixpkgs/nixpkgs-unstable. This mirrors the default <nixpkgs> channel set up by the Nix installer. Anyone who wants the master branch can reference it as nixpkgs/master. And similarly, other branches like nixpkgs/nixos-21.11 will still work as they do today.