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.

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• Linux kernel ≥ 3.11 is required (for 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)
• Running in a VM guest is supported, as long as the VM supports virtualization of hardware performance counters. (VMware and KVM are known to work; Xen does not.)