svn propget throws an error if the property doesn't exist, which has caused Arcanist to stop working for us after a recent upgrade to svn 1.9.3 (I believe 1.8 returns with no output)
svn mv <file> <file>_2
arc diff --only
"svn: warning: W200017: Property 'svn:mime-type' not found on '<file>@'
svn: E200000: A problem occurred; see other errors for details
#2 ArcanistSubversionAPI::getSVNProperty(string, string) called at [<arcanist>/src/repository/api/ArcanistSubversionAPI.php:454
Running with head libphutil/arcanist/phabricator