[Nix-dev] `hydra_eval_job' shouldn't require optional arguments

[Ludovic Courtès]

Hi,

[I tried to report it through YellowGrass but the Captcha stuff keeps
telling me "text entered did not match text in image".]

Consider this:

    { optional ? null }:
    
    {
      bar = "yes";
    }

and:

    $ hydra_eval_jobs $PWD/t.nix 
    warning: `--gc-roots-dir' not specified
    <?xml version='1.0' encoding='utf-8'?>
    <jobs>
      <error location="" msg="job `' requires an argument named `optional'">
      </error>
    </jobs>

I would expect `hydra_eval_jobs' to use the default value of `optional'
instead of returning an error.

Thanks,
Ludo'.