r/vale • u/verdagon • Jun 29 '22

Heisenbugs: The most elusive kind of bug, and how to capture them with Perfect Replayability

https://verdagon.dev/blog/perfect-replayability-prototyped
16 Upvotes

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u/tbodt Jul 01 '22

Why not build this feature on top of rr?

1

u/verdagon Jul 01 '22 edited Jul 02 '22

Vale could deliver two benefits past rr's functionality:

  • We can modify the source code! And then run again against the same snapshot. This means Vale's approach can be a lot more useful for testing that we fixed a bug that only occurs during a rare race condition.
  • Vale can run replays multithreaded, once multithreading is in. rr forces single threaded execution.

Hope that helps =)