"Failed to checkout plugin" error

[dhess]

This isn't an issue with this plugin per se, but the NixOS Buildkite service doesn't include a plugin-path setting for the agent, and so when you try to run this plugin, you will initially get this error:

Preparing plugins |
$ cd /var/lib/buildkite-agent-test/builds/spunup-a-test-1/hackworthltd/hacknix
🚨 Error: Failed to checkout plugin nix-buildkite: Can't checkout plugin without a `plugins-path`

This can be fixed by adding the following to the NixOS Buildkite agent config:

  extraConfig = ''
    plugins-path="${config.services.buildkite-agents.test.dataDir}/plugins"
  '';

This should probably be added to this project's documentation.