We're currently trying out Arcanist and have the following itch holding up adoption:
If a differential revision is created for a bug fix, and accepted by the reviewer, the original creator must perform the wholly automatable task of getting a version of the local copy with that revision applied and running "arc commit" on SVN. This can be unnecessarily problematic if the developer has already moved onto another development task and does not have a clean working copy.
Firstly, how does Arcanist handle the subsequent local mods? Will it apply a patch over local mods and svn commit only the modifications listed under that revision? What if there are conflicts?
Secondly, is there a way to automate the svn commit for these special bug fixes large enough to warrant a review but small enough that the extra overhead of the final "arc commit" becomes significant? This can be automated in other ways, but there are concerns for author corruption etc.