Re: Converting repo from HG, `git filter-branch --prune-empty -- --all` is extremely slow and errors out.

> Indeed, I remember writing my own simplified version of 'git
> filter-branch' that was much faster. If I recall correctly, the trick
> was avoiding 'git write-tree' which can be done if you are not using
> any tree filter, but 'git filter-branch' is not that smart.
>
> If all you want to do is prune empty commits, it should be easy to
> write a script that simply does 'git commit-tree'. I might decide to
> do that based on my script if I have time today.