Function slack_binding_label 

fn slack_binding_label(
    binding: &SlackBinding,
    scope: &str,
    labels: &BTreeSet<String>,
    path: &Path,
) -> Result<String, WorkspaceError>

The label a scope’s slack binding resolves to, or a load error naming the label asked for and the ones that exist: a binding to a workspace forge does not have would leave every Slack tool dead at runtime.