phacility/phabricator · error · Exception

You can not create a relationship to object "%s" because obj

Error message

You can not create a relationship to object "%s" because objects can not be related to themselves.

What it means

The relationship controller forbids relating an object to itself: while looping over added PHIDs, any $add_phid equal to the source object's $src_phid triggers this Exception (caught and shown as an unrelatable-object dialog). Self-referential edges would create nonsense like 'task T depends on task T' and can loop graph algorithms, so they are rejected outright.

Source

Thrown at src/applications/search/controller/PhabricatorSearchRelationshipController.php:94

          ->execute();
        $dst_objects = mpull($dst_objects, null, 'getPHID');
      } else {
        $dst_objects = array();
      }

      try {
        foreach ($add_phids as $add_phid) {
          $dst_object = idx($dst_objects, $add_phid);
          if (!$dst_object) {
            throw new Exception(
              pht(
                'You can not create a relationship to object "%s" because '.
                'the object does not exist or could not be loaded.',
                $add_phid));
          }

          if ($add_phid == $src_phid) {
            throw new Exception(
              pht(
                'You can not create a relationship to object "%s" because '.
                'objects can not be related to themselves.',
                $add_phid));
          }

          if (!$relationship->canRelateObjects($object, $dst_object)) {
            throw new Exception(
              pht(
                'You can not create a relationship (of type "%s") to object '.
                '"%s" because it is not the right type of object for this '.
                'relationship.',
                $relationship->getRelationshipConstant(),
                $add_phid));
          }
        }
      } catch (Exception $ex) {
        return $this->newUnrelatableObjectResponse($ex, $done_uri);

View on GitHub (pinned to 5720a38cfe)

Solutions

Exclude the source PHID from any list you feed to the dialog: array_diff($phids, array($src_phid)).
If you hit it in the UI, just remove the object from the selection - the dialog shows which PHID offended in the message.
For scripts, filter self-references before building the request.
No configuration exists to allow self-relationships; model true self-loops differently (e.g. a separate linked-object field).

Example fix

// before
$add_phids = array_diff($phids, $initial_phids);

// after: also drop self-references
$add_phids = array_diff($phids, $initial_phids, array($src_phid));

Defensive patterns

Strategy: validation

Validate before calling

$add_phids = array_diff($phids, $initial_phids, array($src_phid));

Type guard

function hasNoSelfReference($src_phid, array $add_phids) { return !in_array($src_phid, $add_phids, true); }

Try / catch

try {
  $this->applyRelationshipChanges($object, $add, $rem);
} catch (Exception $ex) {
  return $this->newUnrelatableObjectResponse($ex, $done_uri);
}

Prevention

Filter the current object's PHID out of any generated list before POST
Typeahead config for relationship dialogs should exclude the source object
When computing dependency graphs in scripts, skip edges where src === dst

When it happens

Trigger: POSTing the object's own PHID in the add list - e.g. adding a task to its own subscribers, setting a task as blocking itself ('Maniphest Task: T123'), or dragging the same object into its relationship tokenizer via paste (paste the current object's URI, which the tokenizer resolves to its PHID).

Common situations: Users pasting the object URL into the dialog's typeahead out of curiosity; scripts that compute related-object sets with an off-by-one including the root; merging tasks where source and destination coincide.

Related errors

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/bba9b0a17d9b41f6. Report an issue: GitHub.