It’s been ten years since the first release of “rr”, an open-source record-and-replay debugger with many real-world users. It’s been five years since the release of “Pernosco”, a commercial omniscient debugger with some real-world users. I’ll give a brief overview of these tools and the technology behind them. I’ll explain why users adopted these tools and how they are used in practice. Just as importantly, I’ll present my understanding of why users have NOT adopted these kinds of tools and what we might be able to do about that. I’ll discuss some aspects of the debugging problem where I think academic research would be really useful.

In 2001 Robert graduated with a PhD in computer science from Carnegie Mellon University, supervised by Daniel Jackson and Jeannette Wing, on polymorphic type inference for context-sensitive alias analysis for Java code.

From 2001 to 2004 he worked at IBM Research on dynamic program analysis tools.

From 2000 he moonlighted as a volunteer working on the Mozilla open source project, which became Firefox. In 2005 he moved back to New Zealand to work full-time on Firefox’s browser engine; Mozilla awarded him the title of Distinguished Engineer. In his last few years at Mozilla he led the development of “rr”, a practical record-and-replay debugger supporting reverse execution, used by many developers inside and outside Mozilla to the present day. He continues as an rr maintainer to this day.

In 2016 he left Mozilla to co-found Pernosco, a startup working on cloud-based, omniscient debugging leveraging rr.

In 2022 he joined Google Research to work on various projects mostly unrelated to debugging.

He lives in New Zealand and enjoys hiking, board games and lay preaching.