rr VS Replay.io

I think this tool must share a lot techniques and use cases with rr. I wonder how it compares in various aspects. https://rr-project.org/ rr "sells" as a "reversible debugger", but it obviously needs the determinism for its record and replay to work, and AFAIK it employs similar techniques regarding system call interception and serializing on a single CPU. The reversible debugger aspect is built on periodic... - Source: Hacker News / 14 days ago

Https://rr-project.org/ had the same problem. They use the retired conditional branch counter instead of instruction counter, and then instruction steeping until at the correct address. - Source: Hacker News / about 1 month ago

That'll work great for your Distributed QSort Incorporated startup, where the only product is a sorting algorithm. Formal software verification is very useful. But what can be usefully formalized is rather limited, and what can be formalized correctly in practice is even more limited. That means you need to restrict your scope to something sane and useful. As a result, in the real world running thousands of tests... - Source: Hacker News / 3 months ago

The approach of check-pointing computation such that it is resumable and restartable sounds similar to a time-traveling debugger, like rr or WinDbg: https://rr-project.org/ https://learn.microsoft.com/windows-hardware/drivers/debuggercmds/time-travel-debugging-overview. - Source: Hacker News / 3 months ago

Yes, it's called rr. https://rr-project.org/. - Source: Hacker News / 3 months ago

Exactly - that's what we've already built for web development at https://replay.io :) I did a "Learn with Jason" show discussion that covered the concepts of Replay, how to use it, and how it works: - https://www.learnwithjason.dev/travel-through-time-to-debug-javascript Not only is the debugger itself time-traveling, but those time-travel capabilities are exposed by our backend API: -... - Source: Hacker News / 3 months ago

I made a Replay recording of the sandbox:. Source: 11 months ago

Hiya folks! In addition to all my free time spent working on Redux, answering questions, and modding this sub, my day job is working on Replay.io. Today we're thrilled to announce our new Replay for Test Suites feature, which lets you record and time-travel debug Cypress (and Playwright) E2E tests as they ran in CI! Source: 11 months ago

FWIW, the Firefox devs who were doing the WebReplay time travel debugging POC weren't, as far as I know, fired. Instead, they left and started Replay ( https://replay.io ), a true time-traveling debugger for JavaScript. I joined Replay as a senior front-end dev a year ago. It's real, it works, we're building it, and it's genuinely life-changing as a developer :) Not sure how well this would have fit into Firefox... - Source: Hacker News / 11 months ago

I also recently did a Learn with Jason show episode based on this, where we went through many of the same topics, and also looked at the Replay.io time-traveling debugger that I build as my day job:. Source: about 1 year ago