GO'S RACE DETECTOR HAS A MUTEX BLIND SPOT

Summary from the TLDR Web Dev newsletter

Go's race detector has a blind spot when detecting data races involving mutex-protected code. While the detector can identify races that don't involve synchronization primitives regardless of timing, it may miss races in mutex-protected sections depending on the execution order. Despite this limitation, Go's race detector is one of the best tools available for dynamic race detection to keep code relatively race-free.