Pyre recently switched our backend build to Ocaml 5.0.0.
It was a smooth switch for the most part. I know a lot of work went into this and we appreciate it!
We did notice one surprising regression - we had to remove a call to Gc.stat that we had for telemetry tracking.
The problem was that when we type-checked our largest Python codebase, that call was taking more than 50 seconds (in 4.14, the same call took well under 1 second).
After asking around we’ve learned that:
- the Gc.stat implementation did change and some regression is expected
- we should have been using Gc.quick_stat anyway, which is a change I’ll make soon
Nonetheless we thought it might be good to report this in case the slowness we experienced comes as a surprise.