Trying to use the hydra-eval-jobs binary outside hydra

Development Hydra
1

I try to build larger nix projects in a argo workflow instead of hydra.
I have very little experience with hydra but try to use the job runner in another environment and reuse code / functionality.
When I try to run hydra itself:
./result/bin/hydra-eval-jobs --gc-roots-dir /tmp/roots -I . --flake $(pwd)

error:
       … in the condition of the assert statement

         at /call-flake.nix:66:13:

           65|           if node.flake or true then
           66|             assert builtins.isFunction flake.outputs;
             |             ^
           67|             result

       … while calling the 'isFunction' builtin

         at /call-flake.nix:66:20:

           65|           if node.flake or true then
           66|             assert builtins.isFunction flake.outputs;
             |                    ^
           67|             result

       (stack trace truncated; use '--show-trace' to show the full trace)

       error: access to URI 'github:NixOS/nixpkgs/e9f06adb793d1cca5384907b3b8a4071d5d7cb19' is forbidden in restricted mode

I’m trying to understand what hydra does. There seems to be a fetch stage that I’m missing. Is there a easy way to fetch the sources in a way for this to execute ?