```
exception 'AphrontQueryParameterException' with message 'Array for %Ls conversion is empty. Query: buildablePHID IN (%Ls)' in /srv/phabricator/libphutil/src/xsprintf/qsprintf.php:260
2 Stack trace:
3 #0 /srv/phabricator/libphutil/src/xsprintf/qsprintf.php(135): _qsprintf_check_type(Array, 'Ls', 'buildablePHID I...')
4 #1 /srv/phabricator/libphutil/src/xsprintf/xsprintf.php(63): xsprintf_query(Object(AphrontMySQLiDatabaseConnection), 'buildablePHID I...', 19, Array, 22)
5 #2 /srv/phabricator/libphutil/src/xsprintf/qsprintf.php(66): xsprintf('xsprintf_query', Object(AphrontMySQLiDatabaseConnection), Array)
6 #3 /srv/phabricator/phabricator/src/applications/harbormaster/query/HarbormasterBuildableQuery.php(196): qsprintf(Object(AphrontMySQLiDatabaseConnection), 'buildablePHID I...', Array)
7 #4 /srv/phabricator/phabricator/src/applications/harbormaster/query/HarbormasterBuildableQuery.php(70): HarbormasterBuildableQuery->buildWhereClause(Object(AphrontMySQLiDatabaseConnection))
8 #5 /srv/phabricator/phabricator/src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php(219): HarbormasterBuildableQuery->loadPage()
9 #6 /srv/phabricator/phabricator/src/applications/harbormaster/step/HarbormasterWaitForPreviousBuildStepImplementation.php(80): PhabricatorPolicyAwareQuery->execute()
10 #7 /srv/phabricator/phabricator/src/applications/harbormaster/step/HarbormasterWaitForPreviousBuildStepImplementation.php(34): HarbormasterWaitForPreviousBuildStepImplementation->getBlockers(Object(PhabricatorRepositoryCommit), Object(HarbormasterBuildPlan), Object(HarbormasterBuild))
11 #8 /srv/phabricator/phabricator/src/applications/harbormaster/worker/HarbormasterTargetWorker.php(46): HarbormasterWaitForPreviousBuildStepImplementation->execute(Object(HarbormasterBuild), Object(HarbormasterBuildTarget))
12 #9 /srv/phabricator/phabricator/src/infrastructure/daemon/workers/PhabricatorWorker.php(85): HarbormasterTargetWorker->doWork()
13 #10 /srv/phabricator/phabricator/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php(123): PhabricatorWorker->executeTask()
14 #11 /srv/phabricator/phabricator/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php(19): PhabricatorWorkerActiveTask->executeTask()
15 #12 /srv/phabricator/libphutil/src/daemon/PhutilDaemon.php(85): PhabricatorTaskmasterDaemon->run()
16 #13 /srv/phabricator/libphutil/scripts/daemon/exec/exec_daemon.php(112): PhutilDaemon->execute()
17 #14 {main}
```