missing_defaults_at_macro.yaml:12:3: In project 'sample-project'
    - project:
      ^
missing_defaults_at_macro.yaml:15:7: Defined here
        - sample-job
          ^
missing_defaults_at_macro.yaml:7:3: In job template 'sample-job'
    - job-template:
      ^
missing_defaults_at_macro.yaml:10:7: While expanding builder macro call 'sample-builder'
        - sample-builder
          ^
missing_defaults_at_macro.yaml:3:15: Builder macro 'sample-builder' wants defaults 'missing-defaults', but it was never defined
        defaults: missing-defaults
                  ^