Stacktrace is as follows:
```
> ./bin/repository parents CI
Rebuilding "rCI"...
Rebuilding branch "master"...
Rebuilding branch "X"...
Rebuilding branch "Y"...
Rebuilding branch "Z"...
Found 1,296 total commit(s); updating...
[2014-05-27 23:09:52] EXCEPTION: (Exception) Unknown commit "a1d5645eabf502a8d830c5d52e1e9f1953939957"! at [/usr/src/phabricator/src/applications/repository/management/PhabricatorRepositoryManagementParentsWorkflow.php:114]
#0 PhabricatorRepositoryManagementParentsWorkflow::rebuildRepository(Object PhabricatorRepository) called at [/usr/src/phabricator/src/applications/repository/management/PhabricatorRepositoryManagementParentsWorkflow.php:43]
#1 PhabricatorRepositoryManagementParentsWorkflow::execute(Object PhutilArgumentParser) called at [/usr/src/libphutil/src/parser/argument/PhutilArgumentParser.php:396]
#2 PhutilArgumentParser::parseWorkflowsFull(Array of size 14 starting with: { PhabricatorRepositoryManagementCacheWorkflow => Object PhabricatorRepositoryManagementCacheWorkflow }) called at [/usr/src/libphutil/src/parser/argument/PhutilArgumentParser.php:292]
#3 PhutilArgumentParser::parseWorkflows(Array of size 14 starting with: { PhabricatorRepositoryManagementCacheWorkflow => Object PhabricatorRepositoryManagementCacheWorkflow }) called at [/usr/src/phabricator/scripts/repository/manage_repositories.php:22]
```