I like a lot that for a simple change that may involve adding and / or editing files, I can just call arc diff and Arcanist will prompt to include or not each change. That allows to skip the git commit step.

However, if arc land fails due to a merge conflict and you call git mergetool, resolve it and call again arc diff, the fixed revision is correctly pushed to Differential, but it will fail again if you try to arc land it.

The solution is to call git commit before calling arc land.

For consistency the simple case described above, and also to avoid an extra step, it would be nice if arc diff could take care of calling git commit (it looks like there's already a commit message ready in there anyway), or at least prompt for it.