By default spotlight won’t search through system files (e.g. anything that lives in
~/Library/), which gave me a bit of a headache today when I was looking for where I had put an emacs mode file that I was initializing in my
Preferences.el in Aquamacs.
The trick is to enable “System files” in the “Kind” menu in the Finder spotlight. To do this add a search rule, click on the “Kind” menu, choose “Other” and select “System files” in the list. Wham!