When using arc to make a diff, we occasionally run into a situation where arc spits out this error message:

Usage Exception: Base revisions of changed paths are mismatched. Update all paths to the same base revision before creating a diff:

Which a simple svn update will fix, not a huge deal, but would it be possible to move this check earlier in the arc workflow? The issue for us is that it runs at the very end, after linting and after unit tests run. If tests take a while to run (can be the case in some of our projects), it can be frustrating to get this error message, svn update, then kick off tests/linting all over again.

If it isn't a terribly intensive check, perhaps it's best at the beginning and at the end of the workflow (just in case something changes in the working copy right before the diff is submitted, but after arc started)?