Bug Fixing

Posted by Ravikiran K.S. on January 1, 2006

If you can’t re-create the bug on demand, then your chances of fixing it will be nil.

Step 1: Enter the bug in your case tracking system Record these three things in each bug report:

What the user was doing
What they were expecting
What happened instead

Step 2: Search the error message Search for error phrases in bug-tracking system

Step 3: Identify the immediate line of code where the bug occurs If its a crash, its a boon. Logs are pristine.

Step 4: Identify the flow-of-code/code-sequence where the bug actually occurs This is the most daunting part. Most of times, this isn’t very apparent.

Step 5: Identify the species of bug

Error in external/system library - Then most likely error is in your code, in the way that those routines are used. Look into manpages, documentation, etc.
Coding errors - Off-By-One, Unhandled return value, Unexpected NULL, Bad input, Assignments instead of comparisons, Buffer overflow & Index Out-of-range, Wrong variable type used (int instead of long), constants are wrong,
Design errors - Race condition, Invalid state, Certain assumptions don’t match in field (ex, constant fields, etc)

Some of the debugging tricks don’t always apply.