I tried the [Phabricator sprint extension](https://github.com/wikimedia/phabricator-extensions-Sprint) and get following error when trying to access `/project/sprint/`:
```
Unhandled Exception ("AphrontParameterQueryException")
Array for %Ls conversion is empty. Query: phid IN (%Ls)
```
The webserver error log shows:
```
[2015-02-09 18:26:21] EXCEPTION: (AphrontParameterQueryException) Array for %Ls conversion is empty. Query: phid IN (%Ls) at [<phutil>/src/xsprintf/qsprintf.php:252], referer: https://${MY_HOST}/applications/
#0 _qsprintf_check_type(array, string, string) called at [<phutil>/src/xsprintf/qsprintf.php:129], referer: https://${MY_HOST}/applications/
#1 xsprintf_query(AphrontMySQLiDatabaseConnection, string, integer, array, integer) called at [<phutil>/src/xsprintf/xsprintf.php:69], referer: https://${MY_HOST}/applications/
#2 xsprintf(string, AphrontMySQLiDatabaseConnection, array) called at [<phutil>/src/xsprintf/qsprintf.php:64], referer: https://${MY_HOST}/applications/
#3 qsprintf(AphrontMySQLiDatabaseConnection, string, array) called at [<phabricator>/src/applications/project/query/PhabricatorProjectQuery.php:270], referer: https://${MY_HOST}/applications/
#4 PhabricatorProjectQuery::buildWhereClause(AphrontMySQLiDatabaseConnection) called at [<phabricator>/src/applications/project/query/PhabricatorProjectQuery.php:130], referer: https://${MY_HOST}/applications/
#5 PhabricatorProjectQuery::loadPage() called at [<phabricator>/src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php:227], referer: https://${MY_HOST}/applications/
#6 PhabricatorPolicyAwareQuery::execute() called at [<sprint>/controller/SprintListController.php:67], referer: https://${MY_HOST}/applications/
#7 SprintListController::loadAllSprints(PhabricatorUser, array) called at [<sprint>/controller/SprintListController.php:16], referer: https://${MY_HOST}/applications/
#8 SprintListController::processRequest() called at [<phabricator>/src/aphront/AphrontController.php:33], referer: https://${MY_HOST}/applications/
#9 AphrontController::handleRequest(AphrontRequest) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:196], referer: https://${MY_HOST}/applications/
#10 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:121], referer: https://${MY_HOST}/applications/
#11 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phabricator>/webroot/index.php:19], referer: https://${MY_HOST}/applications/
```
I installed the extension by adding it to `load-libraries` in `local.json`.
Phabricator Version: cdd8dcbf17bb4700cf22937ce0f3db43126ee5f3
Arcanist Version: 59640f7eae3f7c0a352c18e784fb55acb7967991
libphutil Version: 2b23ac46a8473304b68afa16c353539e18e2e9f4
The sprint extension is at: 24d59c2fd10eec0ad8251ab26e4fb8f1eb345d97