People are rarely happy to see a stack trace. A stack trace often appears when software encounters an exception, an unexpected error which can't be handled gracefully and therefore most stop execution of the program. What the stack trace shows is what was happening in the moments leading up to the bug. The stack is called a stack because each item (each function call) is stacked on top of the previous one in a special part of computer memory called the stack. Most computers and programming languages work with a stack. In programs written in programming languages without side effects, a...