phacility/phabricator · error · Exception

Invalid or unknown object ("%s") for land operation, expecte

Error message

Invalid or unknown object ("%s") for land operation, expected Differential Revision.

What it means

Drydock's "land" repository operation can only merge a Differential revision's staging-area ref into a target branch, so getWorkingCopyMerges() validates that the operation's object PHID resolves to a DifferentialRevision before building the merge list. If the object is missing or of any other type, it throws this plain Exception, which surfaces as a failed repository operation in Harbormaster. In practice this indicates corrupted operation state or a custom/3rd-party operation type reusing the land implementation with the wrong object.

Source

Thrown at src/applications/drydock/operation/DrydockLandRepositoryOperation.php:53

        return pht(
          'Revision landed into %s.',
          $repository->getMonogram());
    }
  }

  public function getWorkingCopyMerges(DrydockRepositoryOperation $operation) {
    $repository = $operation->getRepository();
    $merges = array();

    $object = $operation->getObject();
    if ($object instanceof DifferentialRevision) {
      $diff = $this->loadDiff($operation);
      $merges[] = array(
        'src.uri' => $repository->getStagingURI(),
        'src.ref' => $diff->getStagingRef(),
      );
    } else {
      throw new Exception(
        pht(
          'Invalid or unknown object ("%s") for land operation, expected '.
          'Differential Revision.',
          $operation->getObjectPHID()));
    }

    return $merges;
  }

  public function applyOperation(
    DrydockRepositoryOperation $operation,
    DrydockInterface $interface) {
    $viewer = $this->getViewer();
    $repository = $operation->getRepository();

    $cmd = array();
    $arg = array();

View on GitHub (pinned to 5720a38cfe)

Solutions

Inspect the failing operation's objectPHID (Drydock repository operation UI or `drydock.repositoryoperation.search`) and confirm the object exists and is a DifferentialRevision
If the referenced revision was deleted, release/cancel the orphaned operation instead of retrying it
If you wrote custom code that builds the operation, always pass the revision PHID via setObjectPHID()
If using the land implementation for non-Differential objects, stop: it is hard-wired to Differential

Example fix

// before
$operation = id(new DrydockRepositoryOperationQuery())
  ->setViewer($viewer)
  ->withIDs(array($id))
  ->executeOne();
$merges = $impl->getWorkingCopyMerges($operation);
// Exception: Invalid or unknown object ("PHID-X") for land operation...

// after
$object = $operation->getObject();
if (!($object instanceof DifferentialRevision)) {
  return new Aphront404Response(); // or cancel the operation
}
$merges = $impl->getWorkingCopyMerges($operation);

Defensive patterns

Strategy: type-guard

Type guard

// PHP type guard before requesting merges:
function isLandableObject(DrydockRepositoryOperation $operation) {
  return $operation->getObject() instanceof DifferentialRevision;
}

if (!isLandableObject($operation)) {
  // cancel the operation / show a clear error instead of letting land throw
}

Try / catch

catch (Exception $ex) { if the message contains 'for land operation, expected Differential Revision', treat the operation as corrupt: cancel/release it and surface a UI error; do not retry }

Prevention

Always create land operations with the DifferentialRevision PHID bound at creation time
Guard operation handling code with instanceof on getObject() before calling land-specific methods
Prevent deletion/abandonment of revisions that have live land operations, or cancel those operations on deletion

When it happens

Trigger: A DrydockRepositoryOperation row whose objectPHID points at a non-revision object (or a deleted/inaccessible object); calling DrydockLandRepositoryOperation::getWorkingCopyMerges() manually on an operation whose object was never a revision; an operation created by custom code that skips the revision binding.

Common situations: Database-level tampering or restore-from-backup leaving orphaned operation rows; extensions that subclass the land operation for non-Differential objects; deleting a Differential revision while its land operation is still queued.

Related errors

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/c7c6cc77c8e6e8bf. Report an issue: GitHub.