I'm seeing a lot of these errors in our `phd` logs:
```
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] [2015-03-07 10:41:31] EXCEPTION: (PhutilProxyException) Error while updating the "rPP" repository. {>} (CommandException) Command failed with error #255!
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] COMMAND
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] '/usr/src/phabricator/bin/repository' update '--no-discovery' -- 'PP'
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] STDOUT
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] (empty)
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] STDERR
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] [2015-03-07 10:41:31] EXCEPTION: (Exception) Lock 'global:phabricator:PhabricatorRepositoryManagementUpdateWorkflow:PP is not locked by this process! at [<phutil>/src/filesystem/PhutilLock.php:195]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] arcanist(head=master, ref.master=c36b4ceb1849), phabricator(head=master, ref.master=85f4bdc2ac74), phlab(head=master, ref.master=4689d11dbe69), phutil(head=master, ref.master=eaa6ebecef8e)
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #0 PhutilLock::unlock() called at [<phabricator>/src/applications/repository/management/PhabricatorRepositoryManagementUpdateWorkflow.php:102]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #1 PhabricatorRepositoryManagementUpdateWorkflow::execute(PhutilArgumentParser) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:396]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #2 PhutilArgumentParser::parseWorkflowsFull(array) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:292]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #3 PhutilArgumentParser::parseWorkflows(array) called at [<phabricator>/scripts/repository/manage_repositories.php:22]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] at [<phutil>/src/future/exec/ExecFuture.php:416]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] arcanist(head=master, ref.master=c36b4ceb1849), phabricator(head=master, ref.master=85f4bdc2ac74), phlab(head=master, ref.master=4689d11dbe69), phutil(head=master, ref.master=eaa6ebecef8e)
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #0 phlog(PhutilProxyException) called at [<phabricator>/src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php:364]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #1 PhabricatorRepositoryPullLocalDaemon::resolveUpdateFuture(PhabricatorRepository, ExecFuture, integer) called at [<phabricator>/src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php:199]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #2 PhabricatorRepositoryPullLocalDaemon::run() called at [<phutil>/src/daemon/PhutilDaemon.php:179]
Daemon 4800 STDE [Sat, 07 Mar 2015 10:41:32 +1100] #3 PhutilDaemon::execute() called at [<phutil>/scripts/daemon/exec/exec_daemon.php:119]
```