A comment on my old blog post about the history of reverse execution gave me a pointer to a fairly early example of replay debugging. The comment pointed at a 2002 blog post which in turn pointed at a 1999 LWN.net text which almost in passing describes a seemingly working record-replay debugger from 1995. The author was a Michael Elizabeth Chastain, of whom I have not managed to find any later traces.
For some reason, when I think of reverse execution and debugging, the sound track that goes through my head is a UK novelty hit from 1987, “Star Trekkin” by the Firm. It contains the memorable line “we’re only going forward ’cause we can’t find reverse“. To me, that sums up the history of reverse debugging nicely. The only reason we are not all using it every day is that practical reverse debugging has not been available until quite recently. However, in the past ten years, I think we can say that software development has indeed found reverse. It took a while to get there, however. This is the first of a series of blog posts that will try to cover some of the history of reverse debugging. The text turned out to be so long that I had to break it up to make each post usefully short. Part two is about research, and part three about products.
Continue reading “Reverse History Part One”