Debugging software

General notes

Finding a bug is different that fixing it
We spend more time debugging than programming
Debugging is part of the process
Do a research before starting (eg on Search Engines, ask a colleague etc)
Understand the system/app before starting
Get a fresh view, eg ask another person to check the problem
Try to reproduce the problem on a clean installation
Use log files (eg syslog) and an audit trail
Format logs (eg with multitail)
Show contextual info on the Logs (eg browser, env, user, date etc)
Always take notes and keep logs
Create small experiments with git branches
Create a script/method that can recreate the app for every test (eg with docker, clean backup etc)
Prefer to store log files on the system and not in the (web) screen
Start with the "easy" to fix errors
Do not debug online. Make a local copy of the app. This may not be the case where the problem is from the server setup
Thinking stragetically is more important than applying funcy debug tools
"Hard to fix" bugs are the one that appear when two "bug free" components interact to create the bug
Prepare to continue the debug on another day
If your solution is important publish (eg as a patch) it on the appropriate place (eg on Drupal.org issue)
Document the process when the bug is fixed
Sometimes you have to live with a bug wihout fixing it