rr - Record and Replay Framework. An alternative to GDB

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. You can record a failure once, then debug the recording, deterministically, as many times as you want. The same execution is replayed every time.

rr also provides efficient reverse execution under gdb. Set breakpoints and data watchpoints and quickly reverse-execute to where they were hit. rr works on real applications and is used by many developers to fix real bugs. It makes debugging hard bugs much easier, but also speeds up debugging of easy bugs.