We have three `PhabricatorRepositoryGitCommitMessageParserWorker` tasks that are constantly failing. I am seeing the following error in the daemon logs:
```
[04-Dec-2014 22:42:28 Australia/Sydney] [2014-12-04 22:42:28] EXCEPTION: (PhutilProxyException) Error while executing task ID 15162574 from queue. {>} (AphrontQueryExcept
ion) #1048: Column 'authorPHID' cannot be null at [<phutil>/src/aphront/storage/connection/mysql/AphrontBaseMySQLDatabaseConnection.php:308]
[04-Dec-2014 22:42:28 Australia/Sydney] #0 AphrontBaseMySQLDatabaseConnection::throwQueryCodeException(integer, string) called at [<phutil>/src/aphront/storage/connection/mysql/AphrontBaseMySQLDatabaseConnection.php:275]
[04-Dec-2014 22:42:28 Australia/Sydney] #1 AphrontBaseMySQLDatabaseConnection::throwQueryException(mysqli) called at [<phutil>/src/aphront/storage/connection/mysql/AphrontBaseMySQLDatabaseConnection.php:181]
[04-Dec-2014 22:42:28 Australia/Sydney] #2 AphrontBaseMySQLDatabaseConnection::executeRawQuery(string) called at [<phutil>/src/xsprintf/queryfx.php:6]
[04-Dec-2014 22:42:28 Australia/Sydney] #3 queryfx(AphrontMySQLiDatabaseConnection, string, string, string, array, string)
[04-Dec-2014 22:42:28 Australia/Sydney] #4 call_user_func_array(string, array) called at [<phutil>/src/aphront/storage/connection/AphrontDatabaseConnection.php:26]
[04-Dec-2014 22:42:28 Australia/Sydney] #5 AphrontDatabaseConnection::query(string, string, string, array, string) called at [<phabricator>/src/infrastructure/storage/lisk/LiskDAO.php:1216]
[04-Dec-2014 22:42:28 Australia/Sydney] #6 LiskDAO::insertRecordIntoDatabase(string) called at [<phabricator>/src/infrastructure/storage/lisk/LiskDAO.php:1070]
[04-Dec-2014 22:42:28 Australia/Sydney] #7 LiskDAO::insert() called at [<phabricator>/src/infrastructure/storage/lisk/LiskDAO.php:1039]
[04-Dec-2014 22:42:28 Australia/Sydney] #8 LiskDAO::save() called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:697]
[04-Dec-2014 22:42:28 Australia/Sydney] #9 PhabricatorApplicationTransactionEditor::applyTransactions(ManiphestTask, array) called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionCommentEditor.php:89]
[04-Dec-2014 22:42:28 Australia/Sydney] #10 PhabricatorApplicationTransactionCommentEditor::applyEdit(ManiphestTransaction, ManiphestTransactionComment) called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:695]
[04-Dec-2014 22:42:28 Australia/Sydney] #11 PhabricatorApplicationTransactionEditor::applyTransactions(ManiphestTask, array) called at [<phabricator>/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php:513]
[04-Dec-2014 22:42:28 Australia/Sydney] #12 PhabricatorRepositoryCommitMessageParserWorker::closeTasks(PhabricatorUser, string, PhabricatorRepository, PhabricatorRepositoryCommit, string) called at [<phabricator>/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php:228]
[04-Dec-2014 22:42:28 Australia/Sydney] #13 PhabricatorRepositoryCommitMessageParserWorker::updateCommitData(DiffusionCommitRef) called at [<phabricator>/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryGitCommitMessageParserWorker.php:15]
[04-Dec-2014 22:42:28 Australia/Sydney] #14 PhabricatorRepositoryGitCommitMessageParserWorker::parseCommit(PhabricatorRepository, PhabricatorRepositoryCommit) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php:44]
[04-Dec-2014 22:42:28 Australia/Sydney] #15 PhabricatorRepositoryCommitParserWorker::doWork() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:91]
[04-Dec-2014 22:42:28 Australia/Sydney] #16 PhabricatorWorker::executeTask() called at [<phabricator>/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php:156]
[04-Dec-2014 22:42:28 Australia/Sydney] #17 PhabricatorWorkerActiveTask::executeTask() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php:19]
[04-Dec-2014 22:42:28 Australia/Sydney] #18 PhabricatorTaskmasterDaemon::run() called at [<phutil>/src/daemon/PhutilDaemon.php:91]
[04-Dec-2014 22:42:28 Australia/Sydney] #19 PhutilDaemon::execute() called at [<phutil>/scripts/daemon/exec/exec_daemon.php:111]
```