ifd

gistfile1.txt

# https://nixos.wiki/wiki/Import_From_Derivation
# https://discourse.nixos.org/t/how-to-import-a-derivation-with-import/15375
# https://nixos.org/manual/nix/stable/language/builtins#builtins-import
# https://nixos.org/manual/nix/stable/language/values.html#type-string
let
  pkgs = import <nixpkgs> {};
  derivation-to-import = pkgs.writeText "inner" "5";
  imported-nix-value = import derivation-to-import;
in pkgs.writeText "foo" ''
   The value from the inner derivation was: ${toString imported-nix-value}
   ''

ifd1.nix

# https://nixos.wiki/wiki/Import_From_Derivation
# https://discourse.nixos.org/t/how-to-import-a-derivation-with-import/15375
# https://nixos.org/manual/nix/stable/language/builtins#builtins-import
# https://nixos.org/manual/nix/stable/language/values.html#type-string
let
  pkgs = import <nixpkgs> {};

  derivation-to-import = pkgs.writeText "inner" ''
      pkgs :
        pkgs.runCommand "imported" {}
            ''' 
            sleep 6
            # This is the out of the imported derivation,
            # not of the outer derivation
            # https://releases.nixos.org/nix-dev/2015-December/019018.html
            echo 5 > ''$out
            '''
  '';

  imported-nix-value = import derivation-to-import pkgs;
in pkgs.writeText "outer" ''
   The value from the inner derivation was: ${imported-nix-value}
   ''