No search of any kind: no repo-name filter on the index, no code search. Repo-name search is cheap (SQL). Code search needs an indexer — likely a separate opt-in component; even git grep over a single repo from the web would help.
repository and code search #7
Discussion
Shipped in 4f3bd48 and live. repo search matches name/description/topics across visible repos; repo grep <owner/name> [--ref] is a literal case-insensitive git grep (5s timeout, 200-match cap, binaries skipped). Web: ?q= filter on the index and a search tab per repo with marked matches linking to blob #L anchors. Private repos stay invisible in every path. A cross-repo code-search indexer stays future work if ever needed.