Software bugs

According to a study by Cambridge University, software bugs cost the economy 312 billion (yes, with a "b") per year (see this link for the full article). The study also found that software developers spend up to 50% of their time finding and fixing bugs. This certainly emphasizes the importance of not just writing clean, well-commented code, but also being sure to perform thorough testing of the code. As a programmer, I find that sometimes the hardest part of debugging is reproducibility. Someone will run your program and find a bug, but then they can't remember exactly what they did to get the error. The article mentioned the concept of "reversible debugging", which essentially records everything that a program does so that when a bug is found, the developer can more easily find the cause. I would imagine that having a tool that implemented this concept would be incredibly helpful when it came to finding and fixing a bug. The article was not clear about whether this type of debugging is only used during development or whether it could be "attached" the deployment program as well. Obviously, having a tool that recorded everything the program does while an actual user is using it could be a big legal issue depending on exactly what the program itself does (i.e. you wouldn't want this debugger attached to a banking app). However, using a reversible debugger during alpha and beta testing could be extremely helpful since it would allow the developer to more easily find and fix bugs while the tool is in use.