Yesterday I was playing around with sapling with a large existing git(hub) repo.

The biggest pain point I had was that there are dozens of scripts in the repo written expecting that git commands will work, which meant that I couldn't get the repo to work with sapling without patching in a bunch of changes across the repo first.
Most of the changes are ultimately pretty easy to convert (eg most scripts do ROOT=$(git rev-parse --show-toplevel) which can simply be ROOT=$(sl root)), but there are some that are less trivial (like git ls-files <pattern>). Once I patched all of that it worked well, but obviously I can't commit the conversion!

I would love to know if there's a good way to use both git and sapling at the same time to make it easier to play, learn and test. From what I can tell they seem to be pretty exclusionary right now.