The phabricator:20150503.repositorysymbols.2.php migration triggers a notice, when migrated arcanist project don't have a repository association:
Applying patch 'phabricator:20150503.repositorysymbols.1.sql'... Applying patch 'phabricator:20150503.repositorysymbols.2.php'... [2015-06-01 08:38:28] ERROR 8: Undefined index: repository at [/home/sites/phabricator/web/phabricator/resources/sql/autopatches/20150503.repositorysymbols.2.php:14] arcanist(head=master, ref.master=7b891cd13e70), phabricator(head=master, ref.master=b13171566df9), phutil(head=master, ref.master=ee6d0c3fe26e) #0 require_once(string) called at [<phabricator>/src/infrastructure/storage/management/PhabricatorStorageManagementAPI.php:226] #1 PhabricatorStorageManagementAPI::applyPatchPHP(string) called at [<phabricator>/src/infrastructure/storage/management/PhabricatorStorageManagementAPI.php:191] #2 PhabricatorStorageManagementAPI::applyPatch(PhabricatorStoragePatch) called at [<phabricator>/src/infrastructure/storage/management/workflow/PhabricatorStorageManagementUpgradeWorkflow.php:190] #3 PhabricatorStorageManagementUpgradeWorkflow::execute(PhutilArgumentParser) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:406] #4 PhutilArgumentParser::parseWorkflowsFull(array) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:301] #5 PhutilArgumentParser::parseWorkflows(array) called at [<phabricator>/scripts/sql/manage_storage.php:176] Applying patch 'phabricator:20150503.repositorysymbols.3.sql'...