diff --git a/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php b/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php
--- a/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php
+++ b/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php
@@ -29,8 +29,11 @@
     if ($commit->isUnreachable()) {
       throw new PhabricatorWorkerPermanentFailureException(
         pht(
-          'Commit "%s" has been deleted: it is no longer reachable from '.
-          'any ref.',
+          'Commit "%s" (with internal ID "%s") is no longer reachable from '.
+          'any branch, tag, or ref in this repository, so it will not be '.
+          'imported. This usually means that the branch the commit was on '.
+          'was deleted or overwritten.',
+          $commit->getMonogram(),
           $commit_id));
     }
 
diff --git a/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php b/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php
--- a/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php
+++ b/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php
@@ -23,9 +23,11 @@
           $ex = $task->getExecutionException();
           if ($ex) {
             if ($ex instanceof PhabricatorWorkerPermanentFailureException) {
-              throw new PhutilProxyException(
-                pht('Permanent failure while executing Task ID %d.', $id),
-                $ex);
+              $this->log(
+                pht(
+                  'Task %d was cancelled: %s',
+                  $id,
+                  $ex->getMessage()));
             } else if ($ex instanceof PhabricatorWorkerYieldException) {
               $this->log(pht('Task %s yielded.', $id));
             } else {