{ 
  _bootstrapImportDependency ?
  source:
    if source ? outPath then _bootstrapImportDependency (import source) 
    else
      let
        evil = builtins.tryEval (source {});
      in
      if evil.success then evil.result else source,
  sources ? (import ./npins), nixpkgs-lib ? _bootstrapImportDependency sources.nixpkgs-lib, lib ? nixpkgs-lib.lib }:
{
  lib = rec {
    importDependency = _bootstrapImportDependency;
    melt = defaultNixFile: flakeInputs: 
    let
      outputFun = import defaultNixFile;
      dependencies = builtins.mapAttrs (n: s: importDependency s) sources;
      outputs = 
      if builtins.isFunction outputFun then outputFun dependencies else outputFun;
    in
    outputs;
  };

  # This works because static.
#  checks.x86_64-linux.test = derivation {
#    name = "test-derivation";
#    builder = ":";
#    system = "x86_64-linux";
#  };

  checks = lib.genAttrs [ "x86_64-linux" ] (system: {
    test = derivation {
      name = "test-derivation";
      builder = ":";
      inherit system;
    };
  });
}