Drupal Code Search

When using the interface to Google's mirror of Drupal and contributed module code that was set up by John Forsythe at Drupal Code Search, do not filter by code language type, or valid results will be inexplicably lost.

See this:
http://drupalcodesearch.com/code?q=admin_theme&version=0&language=0&search=Go%21

Versus this:
http://drupalcodesearch.com/code?q=admin_theme&version=0&language=1&search=Go%21

Filtering by version doesn't seem to upset things.

However, from a Drupal root directory on a GNU-Linux / Unix / Mac OSX command line:

grep -nHR admin_theme .

is certainly more sure and complete (but it will only search core and what modules you actually have downloaded, of course).

Resolution