"When something goes wrong with your Linux-based system, you can
try to diagnose it yourself with the many troubleshooting tools
bundled with the operating system. Knowing about these tools, and
how to effectively use them, can help you overcome many of the
common problems on your system. Here's a list of some of the
weapons in your arsenal against Linux problems.
"When an application you successfully compiled fails during run
time, it usually gives you an error. On a lucky day, the error
message might contain details of what went wrong, and give you
clues about what to do to fix the problem. But this is not what
usually happens. Often, error messages are obscure and of little
help in figuring out what went wrong..."