Bots in bad shape, but possibly a good thing for us

Hi, all. You might have noticed this morning that quite a few of the bots have broken with an assertion failure in deserialization. This is mostly a good thing for us, because we suspect that a non-deterministic issue has just gotten a lot more frequent. Doug, Slava, and I are looking into the issue, but meanwhile I’m going to speculatively revert Slava’s commit so we go back to the broken-but-still-mostly-blue state we were in before.

Hoping to squash this very soon.