v0.57.0

• Check the clone is not shallow before reading its history. git clone --depth 1 — the default for
  CI checkouts and quick clones of large repositories — answers every history question with zero:
  zero reverts, zero hotfixes, no contributor count. That reads exactly like a healthy repository, and
  it is the highest-consequence measurement error available here, because what has already gone wrong
  is one of the three questions the whole audit is aimed by.