I used git init to create a fresh repo, then made three commits. Now I want to rebase to go back and amend my first commit, but if I do git rebase -i HEAD~3 it complains! If I try the same with HEAD~2 then it kinda works but only lets me rearrange the last two commits.
How do I refer to the 'commit before there were any commits' or go back and insert an empty commit?
The easy way, with a recent-enough git (this has been out for a long time now so you should have this):
git rebase -i --root
The other easy way, as twalberg noted in a comment, is to use git checkout --orphan to set up to make a new root commit, which you can copy the old commits on top of. (This is what rebase -i --root ends up doing internally anyway.)
来源：https://stackoverflow.com/questions/22992543/how-do-i-git-rebase-the-first-commit