git-filter-branch which does not suffer from these
performance problems or the safety problems (mentioned below). For those
with existing tooling which relies upon git-filter-branch, <em>git
repo-filter</em> also provides
<a href="https://github.com/newren/git-filter-repo/blob/master/contrib/filter-repo-demos/filter-lamely">filter-lamely</a>,
a drop-in git-filter-branch replacement (with a few caveats).  While
filter-lamely suffers from all the same safety issues as
git-filter-branch, it at least ameloriate