See PHI1534. Currently, bin/aphlict notify ... queues a notification task into the daemon queue, but does not actually send it inline. This makes --trace a little confusing, and the success message ("Sent notification.") misleading.
Using PhabricatorWorker::setRunAllTasksInProcess(true); to force the task to execute in-process hits this:
[2019-11-07 14:27:00] EXCEPTION: (PhabricatorWorkerPermanentFailureException) Feed story (with key "6756694889126356052") does not exist or could not be loaded. at [<phabricator>/src/applications/feed/worker/FeedPushWorker.php:15] arcanist(head=stable, ref.master=cc1ff38843c4, ref.stable=db1959900a64), corgi(head=master, ref.master=72dc914db4d4), instances(head=master, ref.master=7ecf93d378a1), libcore(), phabricator(head=master, ref.master=f5f2a0bc5696, custom=9), phutil(head=master, ref.master=39ed96cd818a), services(head=master, ref.master=c4bd119b358e) #0 FeedPushWorker::loadFeedStory() called at [<phabricator>/src/applications/feed/worker/FeedPublisherWorker.php:6] #1 PhabricatorWorker::scheduleTask(string, array) called at [<phabricator>/src/applications/feed/PhabricatorFeedStoryPublisher.php:151] #2 PhabricatorFeedStoryPublisher::publish() called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:3844] #3 PhabricatorApplicationTransactionEditor::publishFeedStory(PhabricatorUser, array, array) called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:1513] #4 PhabricatorApplicationTransactionEditor::publishTransactions(PhabricatorUser, array) called at [<phabricator>/src/applications/transactions/worker/PhabricatorApplicationTransactionPublishWorker.php:21] #5 PhabricatorApplicationTransactionPublishWorker::doWork() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:124] #6 PhabricatorWorker::executeTask() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:163] #7 PhabricatorWorker::scheduleTask(string, array, array) called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:1462] #8 PhabricatorApplicationTransactionEditor::queuePublishing() called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:1386] #9 PhabricatorApplicationTransactionEditor::applyTransactions(PhabricatorUser, array) called at [<phabricator>/src/applications/aphlict/management/PhabricatorAphlictManagementNotifyWorkflow.php:77] #10 PhabricatorAphlictManagementNotifyWorkflow::execute(PhutilArgumentParser) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:457] #11 PhutilArgumentParser::parseWorkflowsFull(array) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:349] #12 PhutilArgumentParser::parseWorkflows(array) called at [<phabricator>/support/aphlict/server/aphlict_launcher.php:23]
I initially thought this was an issue with transaction visibility, but the notification actually goes through, so I think it's really a problem with the story legitimately not being loadable (presumably because this notification/story is unusual).