diff --git a/src/applications/diffusion/ssh/DiffusionMercurialServeSSHWorkflow.php b/src/applications/diffusion/ssh/DiffusionMercurialServeSSHWorkflow.php
--- a/src/applications/diffusion/ssh/DiffusionMercurialServeSSHWorkflow.php
+++ b/src/applications/diffusion/ssh/DiffusionMercurialServeSSHWorkflow.php
@@ -66,17 +66,6 @@
       ->setWillWriteCallback(array($this, 'willWriteMessageCallback'))
       ->execute();
 
-    // TODO: It's apparently technically possible to communicate errors to
-    // Mercurial over SSH by writing a special "\n<error>\n-\n" string. However,
-    // my attempt to implement that resulted in Mercurial closing the socket and
-    // then hanging, without showing the error. This might be an issue on our
-    // side (we need to close our half of the socket?), or maybe the code
-    // for this in Mercurial doesn't actually work, or maybe something else
-    // is afoot. At some point, we should look into doing this more cleanly.
-    // For now, when we, e.g., reject writes for policy reasons, the user will
-    // see "abort: unexpected response: empty string" after the diagnostically
-    // useful, e.g., "remote: This repository is read-only over SSH." message.
-
     if (!$err && $this->didSeeWrite) {
       $repository->writeStatusMessage(
         PhabricatorRepositoryStatusMessage::TYPE_NEEDS_UPDATE,