And no git command lets you change what public history looks like unless you --force the push. So the check is in a different place. That doesn't seem to me to

And no git command lets you change what public history looks like unless you --force the push. So the check is in a different place. That doesn't seem to me to imply that Mercurial's history is "immutable" and git's is "mutable", especially since those words have precise meanings, and even WITH the --force, git doesn't change anything in the history, it just writes out a new history and updates the branch ref to point to the new history. The only thing mutated (in both systems) is the ref to the branch head, right? So aside from warnings and errors being in different places (both before publish time), what is the difference between the two that leads you to argue that one is immutable and one isn't?