Mozilla has announced the release of rr 4.0. The latest release of this tool includes a lot of performance and architectural improvements, bug and stability fixes as well as additional hardware, kernel, and application compatibility.
rr is an open source low overhead record-and-replay debugging tool by Mozilla that is especially good for large C++ applications.
This C++ debugging tool comes with reverse-execution enabled, therefore, is able to support gdb’s reverse-continue, reverse-step, reverse-next, and reverse-finish commands.
Mozilla actively uses this tool to fix real bugs in the Firefox web browser. This tool can be downloaded from here at Github.