Snapcraft parts metadata

I would like to ask about more info of the build-attributes key, from snapcraft help plugins:

  - build-attributes: [attribute1, attribute2]

    A list of special attributes that affect the build of this specific part.
    Supported attributes:

      - no-system-libraries:
        Do not automatically copy required libraries from the system to satisfy
        the dependencies of this part. This might be useful if one knows these
        dependencies will be satisfied in other manner, e.g. via content
        sharing from other snaps.

      - no-install:
        Do not run the install target provided by the plugin's build system.

        Supported by: kbuild

      - debug:
        Plugins that support the concept of build types build in Release mode
        by default. Setting the 'debug' attribute requests that they instead
        build in Debug mode.