rr is a Linux debugging tool that aims to enhance gdb by allowing users to record a failure and debug it deterministically multiple times. This tool provides efficient reverse execution under gdb, enabling the setting of breakpoints and data watchpoints quickly. rr works on real applications and helps developers fix bugs efficiently. It features low overhead, supports various applications, and allows debugging of multiple-process workloads. Controversial information includes rr emulating a single-core machine, which can slow down parallel programs. Unique features include the ability to record test executions until a failure is seen, making debugging easier and more effective.
https://rr-project.org/