A Tricky Herbie Bug

Today I found and fixed a Herbie bug. It had been bothering me for months: even when run with the same seed, Herbie's results are not reproducible. They're almost reproducible! They're close! But a few benchmarks, something like 5 or so, would differ from run to run. The bug was so tricky, so bizarre, that I just had to write about it. The bug I'll keep things short. I first tested a number of…