in git, what ways are there to "lose" a commit in a way that you CAN'T recover using the reflog (so that you need to iterate over every single commit in the repository if you want to find it?

The only ways I know (using git's normal tools) are:

* using `git stash drop` or `git stash pop` to drop a stashed commit
* waiting 90+ days to try to recover the commit (so that it expires from the reflog)
* explicitly deleting the reflog in some way (rm -rf .git, git reflog expire, etc)

@b0rk cleaning too much things with "git gc"?
@amarok
Yes, I thought along that line, too. I was happy to learn:
"git gc tries very hard not to delete objects that are referenced anywhere in your repository. In particular, it will keep not only objects referenced by your current set of branches and tags, but also objects referenced by the index, remote-tracking branches, reflogs (which may reference commits in branches that were later amended or rewound), and anything else in the refs/* namespace."
https://git-scm.com/docs/git-gc
@b0rk
Git - git-gc Documentation

@schmidt_fu @b0rk yeah before running gc, git reflog --expire should be called