After updating to HEAD moments ago, we are getting the following error when pulling from a git repo:
```
$ git pull
phabricator-ssh-exec: Invalid command.
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
```
It seems to be a regression in rP368f3591142ed923bcf2a8bf1a48b746794f2f02: an undefined `$workflow_names` variable is referenced.