You keep looking through the code line by line

It’s five O’Clock now, people are leaving and you’re still looking through functions endlessly into the night. You begin to believe that you have an idea how the code works. What was previously a total mystery is forming into a fuzzy picture of the inner workings of this monstrosity developed in between dozens of engineers, years of commits, and over branches upon branches of additional features. No sign of anything that would cause the error you’re looking for. What do you do?

1. Keep looking through the code line by line, BRING IT ON!
2. Google the Error
3. Strategically add a bunch of debug logging print statements
4. Ask the guy who wrote the code
5. Try running the code again