When I run `arc mail`, where `mail` is aliased to `diff --verbatim`, it fails like so:
PHP Fatal error: __clone method called on non-object in /home/csilvers/khan/devtools/arcanist/src/configuration/ArcanistConfiguration.php on line 34
It looks like the error was introduced in b21a175512f9ea949c87. The idx returned 'undefined' (or whatever php does) when the command is an alias. The rest of the system doesn't care, but the newly introduced `clone` does.
The fix is probably something like:
index = idx($this->buildAllWorkflows(), $command);
return index ? clone(index) : index;