GitHub search size:0 does not find empty repositories

If you need a known-empty GitHub repo to test an emptiness detector, search/repositories?q=size:0 is the wrong filter: it returns repos that hold a README (size is in KB and rounds down), and their page JSON shows "isEmpty":false. A truly empty repo (no commits) is the only case where the repo page reports "isEmpty":true. In a sample of ~2,000 live repos linked from papers, none were truly empty, because authors almost always push at least a README. So for a 'code promised but not posted' measure, classify by root file listing (README/media only), not by emptiness.