In reply to @winston:milli.ng
Baby stepped my way into flakes today for my NixOS system, let see what all the hubub is about

Resources for undertanding flakes:

• https://www.tweag.io/blog/2020-05-25-flakes
• https://www.tweag.io/blog/2020-06-25-eval-cache
• https://www.tweag.io/blog/2020-07-31-nixos-flakes
• https://youtu.be/UeBX7Ide5a0
• https://nixos.wiki/wiki/Flakes

In reply to @jassu:kumma.juttu.asia
Also, is there really no way to override all nixpkgs instances of child flakes? If using more than few flakes it seems to grow into a horror show of a pile of different nixpkgs versions required for using the parent flake.

In reply to @kranzes:matrix.org
https://ayats.org/blog/channels-to-flakes

Thank you.

I am still in a rough in-between state, but its working right now. https://github.com/wrmilling/nixos-configuration

how exactly should I specify runtime dependencies in mkDerivation?

{
  description = "";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let pkgs = import nixpkgs { inherit system; };
      in {
        devShells.default = pkgs.mkShell {
          packages = with pkgs; [ curl fzf jq moreutils screenfetch ];
          shellHook = "echo 'entering dev shell'";
        };
        defaultPackage = pkgs.stdenv.mkDerivation {
          name = "cgpt";
          src = self;
          buildDeps = with pkgs; [ curl fzf jq moreutils screenfetch ];
          buildPhase = "true";
          installPhase = "mkdir -p $out/bin; install -t $out/bin cgpt";
        };
      });
}

it depends on how the thing you're packaging resolves runtime dependencies.

you probably want makeWrapper to provide it a PATH if you search nixpkgs you should find some examples.
maybe look at mons

fyi this question isn't specific to flakes