message: add comment about registry watcher only being run once
diff: @@ -12,6 +12,9 @@ use std::sync::Arc;
  use std::thread;
  use std::time::{Duration, Instant};
  +/// Run the registry watcher
  +/// NOTE: this should only be run once, otherwise crates would be added
  +/// to the queue multiple times.
  pub fn watch_registry(
  build_queue: Arc<BuildQueue>,
  config: Arc<Config>,
  