Wow, these are some serious debugging skills. I also admire the tenacity and the will to investigate the root cause. > I tried setting GOMAXPROCS=1, which tell

Wow, these are some serious debugging skills. I also admire the tenacity and the will to investigate the root cause. > I tried setting GOMAXPROCS=1, which tells Go to only use a single OS-level thread to run Go code. This also stopped the crashes, again pointing strongly to a concurrency issue. I think I would have stopped there.