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rr-debugger
rr
C++2014–2025
rr-debugger / rr

rr

Record and Replay Framework

57Distinct people
68Mentions
0Explicit recommenders
10.7KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Record and Replay Framework

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 12:01:02 AM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year68 dated mentions

Observed mentions: 2014-03-26 12:19:18 UTC to 2025-06-28 03:42:02 UTC.

0369122014-01-01 00:00:00 UTC to 2015-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments20142015-01-01 00:00:00 UTC to 2016-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2016-01-01 00:00:00 UTC to 2017-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 9 mentions; 0 submissions, 9 comments2018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 8 mentions; 0 submissions, 8 comments2019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 11 mentions; 0 submissions, 11 comments20192020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 8 mentions; 0 submissions, 8 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 8 mentions; 0 submissions, 8 comments2022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 8 mentions; 0 submissions, 8 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 5 mentions; 1 submissions, 4 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2025

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20142014-01-01 00:00:00 UTC2015-01-01 00:00:00 UTC303
20152015-01-01 00:00:00 UTC2016-01-01 00:00:00 UTC000
20162016-01-01 00:00:00 UTC2017-01-01 00:00:00 UTC202
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC909
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC808
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC11011
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC808
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC808
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC808
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC202
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC514
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC404

From the project README

An excerpt from the repository, fetched Nov 13, 2026.

Read the project’s introduction
Overview rr is a lightweight tool for recording, replaying and debugging execution of applications (trees of processes and threads). Debugging extends gdb with very efficient reverse-execution, which in combination with standard gdb/x86 features like hardware data watchpoints, makes debugging much more fun. More information about the project, including instructions on how to install, run, and build rr, is at https://rr-project.org. The best technical overview is currently the paper Engineering Record And Replay For Deployability: Extended Technical Report. Or go directly to the installation and building instructions. Please contribute! Make sure to review the pull request checklist before submitting a pull request. If you find rr useful, please add a testimonial. rr development is sponsored by Pernosco and was originated by Mozilla. System requirements Linux kernel >= 4.7 (for support of __WALL in waitid()) rr 5.6.0 worked with kernel 3.11 (requiring PTRACE_SETSIGMASK) rr currently requires either: An Intel CPU with Nehalem (2010) or later microarchitecture. Certain AMD Zen or later processors (see https://github.com/rr-debugger/rr/wiki/Zen) Certain AArch64 microarchitectures (e.g. ARM Neoverse N1 or the Apple Silicon M-series) Running in a VM guest is supported, as long as the VM supports virtualization of hardware performance counters. Some configurations of VMware and KVM are known to work. Some configurations of AWS and GCP VMs are known to work. No configurations of Xen are known to work. AI usage policy When submitting issues or PRs, please clearly indicate how LLMs were used. Issues or PRs which appear LLM-generated but carry no such indications may be closed without comment. When submitting PRs for review, the submitter must be human and take full responsibility for understanding the changes, regardless of how LLMs were used.
Read the full README on GitHub

What Hacker News says

8 sources
I haven’t tried but I’m pretty sure you can change variable values. Aside from it being Linux-only I haven’t encountered the CPU challenges. VM incompatibilities are a different story as I generally only ever run directly on metals when debugging. That being said, it looks like it does work (at least if you have sufficiently new software bits) so may be worth giving it another go: https://github.com/rr-debugger/rr/issues/2806
In Making JavaScript run fast on WebAssembly
> I never said debuggers aren't nice. I said that people prefer print debugging because that is a consistent UI across all environments. You said debuggers require learning "some special syntax", which is not true. This led me to believe that you weren't aware of things I wrote. > VS Code's debugger is nice, but can you seamlessly plug in rr to get time travel features? I haven't tried that, but apparently it should work: https://github.com/rr-debugger/rr/wiki/Using-rr-in-an-IDE > What about Pernosco? The way I understand what Pernosco is (a recording), I would expect that to work as well.
In Print Debugging Should Go Away
I need to throw a million +1's at the `rr` suggestion. it's really great. It's a shame that it doesn't work on ARM processors, but there are good fundamental reasons why it doesn't (it's basically impossible iirc[0]) EDIT - just to mention, rr is mostly compatible with gdb, so frontends such as gdb-many-windows in emacs can work with it. In terms of U.I's I found `gdb-many-windows` to be the nicest i found. While I hate almost everything about the platform, I have to concede that visual studio's debugging integration is actually really good. The only thing I found annoying was that I needed to use Visual Studio for it! (emacs on windows could be annoying enough that I got used to it eventually, but still preferred my linux environment. This is back when working on a cross platform C++ project if that much weren't already clear). [0] https
Read the rest
In Looking for More Debugger

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