[ignoramous]

> https://twitter.com/KentonVarda/status/1189966124688953344

What exactly was the bug though? bool effectively reducing hash(key) to 0 or 1?

[kentonv]

Yes. So almost all keys had a hash code of 1, forcing linear search lookups. Insidious since the code still works, it's just slow -- and only really slow in production, after seeming fine in tests that only put a few items in the map.