[isabelle-dev] mercurial accident

[Lars Hupel]

> The problem behind this: Angeliki got administrative push-access to the
> Isabelle repository, without anybody at Cambridge showing her how to use it.

Before we start blaming individual people, this is not a person problem,
but a tooling problem. Industry has figured out this problem years ago.
One doesn't simply allow pushes to master (or "default" in Mercurial).
CakeML has adopted this too.