We have started using phabricator and noticed that some tasks linger in phabricator/daemon/ and dont get finished.
```
ID Class Owner Expires Failures
807459 PhabricatorRepositoryCommitHeraldWorker 13545:1416311621:ubuntu:2 -101556 3000 143 View Task
807465 PhabricatorRepositoryCommitHeraldWorker 13598:1416311634:ubuntu:2 -101543 3000 143 View Task
807524 PhabricatorRepositoryCommitHeraldWorker 13616:1416311638:ubuntu:2 -101539 3000 143 View Task
807531 PhabricatorRepositoryCommitHeraldWorker 13618:1416311638:ubuntu:2 -101539 3000 143 View Task
```
This seems to only happen to tasks from users that dont exist in Phabricator. After some debugging and Irc chatting. I've found that when:
```
./scripts/repository/reparse.php rEB96bb4893bd14998cf426787617c91c6ca641be97 --herald
[ ] 0.0%[2014-11-19 16:58:26] EXCEPTION: (AphrontParameterQueryException) Array for %Ls conversion is empty. Query: SELECT * FROM %s WHERE userPHID in (%Ls) %Q at [<phutil>/src/xsprintf/qsprintf.php:252]
#0 _qsprintf_check_type(array, string, string) called at [<phutil>/src/xsprintf/qsprintf.php:129]
#1 xsprintf_query(AphrontMySQLiDatabaseConnection, string, integer, array, integer) called at [<phutil>/src/xsprintf/xsprintf.php:63]
#2 xsprintf(string, AphrontMySQLiDatabaseConnection, array) called at [<phutil>/src/xsprintf/qsprintf.php:64]
#3 qsprintf(AphrontMySQLiDatabaseConnection, string, string, array, string)
#4 call_user_func_array(string, array) called at [<phutil>/src/xsprintf/queryfx.php:5]
#5 queryfx(AphrontMySQLiDatabaseConnection, string, string, array, string)
#6 call_user_func_array(string, array) called at [<phutil>/src/xsprintf/queryfx.php:16]
#7 queryfx_all(AphrontMySQLiDatabaseConnection, string, string, array, string)
#8 call_user_func_array(string, array) called at [<phutil>/src/aphront/storage/connection/AphrontDatabaseConnection.php:20]
#9 AphrontDatabaseConnection::queryData(string, string, array, string)
#10 call_user_func_array(array, array) called at [<phabricator>/src/infrastructure/storage/lisk/LiskDAO.php:509]
#11 LiskDAO::loadRawDataWhere(string, array)
#12 call_user_func_array(array, array) called at [<phabricator>/src/infrastructure/storage/lisk/LiskDAO.php:452]
#13 LiskDAO::loadAllWhere(string, array) called at [<phabricator>/src/applications/feed/PhabricatorFeedStoryPublisher.php:196]
#14 PhabricatorFeedStoryPublisher::filterSubscribedPHIDs(array) called at [<phabricator>/src/applications/feed/PhabricatorFeedStoryPublisher.php:124]
#15 PhabricatorFeedStoryPublisher::publish() called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:2293]
#16 PhabricatorApplicationTransactionEditor::publishFeedStory(PhabricatorRepositoryCommit, array, array) called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:807]
#17 PhabricatorApplicationTransactionEditor::applyTransactions(PhabricatorRepositoryCommit, array) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php:69]
#18 PhabricatorRepositoryCommitHeraldWorker::parseCommit(PhabricatorRepository, PhabricatorRepositoryCommit) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php:44]
#19 PhabricatorRepositoryCommitParserWorker::doWork() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:87]
#20 PhabricatorWorker::executeTask() called at [<phabricator>/scripts/repository/reparse.php:281]
```