If you go to step 161 and search for "patlen" you get no results
If you go to step 162 and search for "patlen" you do get a result in editorSelectSyntaxHighlight.
(I made this discovery running a diff between step 184 and my own kilo.c file to see if I had any mistakes, then walking backwards. Thank you very much for making this step-by-step guide available, it's been a great time following along)