I've added a new repository to Phabricator, and all of my commits have been parsed except for one. Whenever the daemon tries to parse the commit, it fails with the following exception:
EXCEPTION: (PhutilProxyException) Error while executing Task ID 1178866. {>} (Exception) Regular expression "/(?:^|\b)(?i:(revert|reverts|reverted|backout|backsout|backedout|back out|backs out|backed out|undo|undoes)\s+)(?i:(commit|commits|change|changes|changeset|changesets|rev|revs|revision|revisions|diff|diffs)\s+)?((?:[rA-Z0-9a-f]+[,\s]*)+)(?:\band\s+([rA-Z0-9a-f]+))?(?i:())?(?:$|\b)/" is invalid! at [<phabricator>/src/infrastructure/customfield/parser/PhabricatorCustomFieldMonogramParser.php:41]
arcanist(head=master, ref.master=4c3d75401f81), phabricator(head=master, ref.master=779a612e4172), phutil(head=master, ref.master=6e8db556dbb9)
#0 <#2> PhabricatorCustomFieldMonogramParser::parseCorpus(string) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php:65]
#1 <#2> PhabricatorRepositoryCommitHeraldWorker::parseCommit(PhabricatorRepository, PhabricatorRepositoryCommit) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php:44]
#2 <#2> PhabricatorRepositoryCommitParserWorker::doWork() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:91]
#3 <#2> PhabricatorWorker::executeTask() called at [<phabricator>/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php:162]
#4 <#2> PhabricatorWorkerActiveTask::executeTask() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php:22]
#5 PhabricatorTaskmasterDaemon::run() called at [<phutil>/src/daemon/PhutilDaemon.php:183]
#6 PhutilDaemon::execute() called at [<phutil>/scripts/daemon/exec/exec_daemon.php:125]I wrote a small test script that reproduces the issue, using the code and regular expression from Phabricator and a sample commit message:
<?php $pattern = '/(?:^|\b)(?i:(revert|reverts|reverted|backout|backsout|backedout|back out|backs out|backed out|undo|undoes)\s+)(?i:(commit|commits|change|changes|changeset|changesets|rev|revs|revision|revisions|diff|diffs)\s+)?((?:[rA-Z0-9a-f]+[,\s]*)+)(?:\band\s+([rA-Z0-9a-f]+))?(?i:())?(?:$|\b)/'; $corpus = "Revert my bug.\n\nThis reverts commit 2db7ea8d243404f73aee00cc2804bd7779aee762o."; $ok = preg_match_all( $pattern, $corpus, $matches, PREG_SET_ORDER | PREG_OFFSET_CAPTURE); if ($ok === false) { throw new Exception(preg_last_error()); } else { print_r($matches); } ?>
When I run it, it throws an exception with message "2", which I believe corresponds to PREG_BACKTRACK_LIMIT_ERROR. I've tried increasing the pcre.backtrack_limit setting to 1000000000, but that just delays the time until the exception is thrown. When I increase the limit even higher, to 1000000000000, the script runs for longer but does not complete within the 4 minute window allocated to the task in Phabricator. (My machine is a Mac Pro with a 3 GHz 8-core processor and 32 GB of RAM.)