Failure Sketches: A Better Way to Debug

One of the main reasons debugging is hard and time consuming is that existing debugging tools do not provide an explanation for the root causes of failures. Additionally, existing techniques either rely on expensive runtime recording or assume existence of a given program input that reliably reproduces the failure, which makes them hard to apply in production scenarios. Consequently, developers spend precious time chasing elusive bugs, resulting in productivity loss. We propose a new debugging technique, called failure sketching, that provides the developer with a high-level explanation for the root cause of a failure. A failure sketch achieves this goal because: 1) it only contains program statements that cause a failure; 2) it shows which program properties differ between failing and successful executions. We argue that failure sketches can be built by combining in-house static analysis and crowdsourced dynamic analysis. For building a failure sketch, we do not assume that developers can reproduce the failure. We show preliminary evidence that failure sketches can significantly improve programmer productivity.