The debug inspector is great, and having code search makes it very powerful. Unfortunately, the code search is far too slow on large code bases. Try starting up the debugger on 280 Slides (http://280slides.com/Editor). Open the debug tab, start debugging, and enter the search term "toggleNotes:" On my computer (2ghz macbook pro), returns zero results. If I try again, still zero results. But, if I then try searching for just "toggle" about half a dozen times, I'll eventually get a couple results. If I slowly add the rest of "Notes:" in, it will eventually find the two "toggleNotes:" results that it should have found originally. It's ok to make me wait as long as it takes, but to proclaim there are zero results when there are obviously not is definitely an error. Of course, being able to do this search in a few seconds or less would make it much more useful.
Yes it is showing "0 results" even while it is still searching. We should not do that. But waiting should give you results eventually.
Only the current source view is searched as of http://trac.webkit.org/changeset/55231