message: Support vendoring with different revs from same git repo
diff: @@ -255,7 +255,9 @@ fn sync(
  let name = if source_id.is_crates_io() {
  CRATES_IO_REGISTRY.to_string()
  } else {
  - source_id.url().to_string()
  + // Remove `precise` since that makes the source name very long,
  + // and isn't needed to disambiguate multiple sources.
  + source_id.with_precise(None).as_url().to_string()
  };
  let source = if source_id.is_crates_io() {
  