def _import_macro_dep_bootstrap_transition(_settings, _attr):
    """The implementation of the `import_macro_dep_bootstrap_transition` transition.

    This transition modifies the config to start using the fake macro
    implementation, so that the macro itself can be bootstrapped without
    creating a dependency cycle, even while every Rust target has an implicit
    dependency on the "import" macro (either real or fake).

    Args:
        _settings (dict): a dict {String:Object} of all settings declared in the
            inputs parameter to `transition()`.
        _attr (dict): A dict of attributes and values of the rule to which the
            transition is attached.

    Returns:
        dict: A dict of new build settings values to apply.
    """
    return {"@rules_rust//rust/settings:use_real_import_macro": False}