What do you do if you cannot resolve a bug? [closed]

Answer 1

Lots of great answers here. One thing that's worked for me in the past is to ask "what can I do to make it totally obvious when this problem has occured?".

For example, if the problem is a corrupted value in a data structure, try building a consistency-check routine that you can run periodically. Also consider implementing all access to the shared data through a set of functions that log each change.

Or, if the problem is a "random" memory overwrite, use a replacement malloc()/free() implementation that traps writing to "free" memory (like electric fence or dmalloc).

Someone else mentioned automating the process of triggering the bug. This is greeat if you can do it. Even having a routine that randomly exercises the program might help in these cases.

Answer 2

Quote taken from "The Cryptonomicon":

"Intuition, like a flash of lightning, lasts only for a second. It generally comes when one is tormented by a difficult decipherment and when one reviews in his mind the fruitless experiments already tried. Suddenly the light breaks through and one finds after a few minutes what previous days of labor were unable to reveal."

Answer 3

Seriously? I do things in this order.

1. Go to bed
2. Ask a colleague
3. Rewrite so the area isn't affected.
4. Ask SO
5. Raise a support ticket with your 3rd party library vendor.

Answer 4

If the bug is so subtle that it takes more than three day to find out, then I usually change the design, because the main point of delivering software is not being called three years later to debug it, so the easier the interaction between components, the better.

Answer 5

For memory related bugs i have found that the Memory Profiling options of Ants Profiler have helped me quite a bit on finding bugs.

Answer 6

Sometimes it takes a little lateral thinking, but every bug is fixable. Sometimes you need to leave it and sleep over it, sometimes it's good to ask someone else to have a quick look (they may see something you haven't), but mostly it's about trying different things, calling up on previous experience. It can be frustrating, but the buzz you get when you do fix it, is like no other!