Data race condition

The value of the shared data will be determined by the interleaving of thread execution. Thread shared data is accessed without holding an appropriate lock, possibly causing a race condition
/src/mongo/db/catalog/index_builds_manager.cpp:423: MISSING_LOCK 152339 Accessing "this->_builders" without holding lock "mongo::IndexBuildsManager._mutex". Elsewhere, "mongo::IndexBuildsManager._builders" is written to with "IndexBuildsManager._mutex" held 2 out of 2 times.