phacility/phabricator · error · Exception

Field "raw_diff" must be non-empty.

Error message

Field "raw_diff" must be non-empty.

What it means

differential.createrawdiff requires the 'diff' parameter containing raw unified-diff text; it is parsed by ArcanistDiffParser and turned into a DifferentialDiff. If the value is null or an empty string (strlen check), the method throws a plain Exception with 'Field "raw_diff" must be non-empty.' - note the message names 'raw_diff' although the actual parameter key is 'diff'.

Source

Thrown at src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php:30

  }

  protected function defineParamTypes() {
    return array(
      'diff' => 'required string',
      'repositoryPHID' => 'optional string',
      'viewPolicy' => 'optional string',
    );
  }

  protected function defineReturnType() {
    return 'nonempty dict';
  }

  protected function execute(ConduitAPIRequest $request) {
    $viewer = $request->getUser();
    $raw_diff = $request->getValue('diff');
    if ($raw_diff === null || !strlen($raw_diff)) {
      throw new Exception(pht('Field "raw_diff" must be non-empty.'));
    }

    $repository_phid = $request->getValue('repositoryPHID');
    if ($repository_phid) {
      $repository = id(new PhabricatorRepositoryQuery())
        ->setViewer($viewer)
        ->withPHIDs(array($repository_phid))
        ->executeOne();
      if (!$repository) {
        throw new Exception(
          pht('No such repository "%s"!', $repository_phid));
      }
    }

    $parser = new ArcanistDiffParser();
    $changes = $parser->parseDiff($raw_diff);
    $diff = DifferentialDiff::newFromRawChanges($viewer, $changes);

View on GitHub (pinned to 5720a38cfe)

Solutions

1. Send the unified diff text under the exact key 'diff' and verify it is non-empty before calling
2. Check the upstream command (git diff / svn diff) actually produced output; fail the pipeline step if not
3. Trim only trailing whitespace - an effectively whitespace-only diff is also useless
4. Use the response's diffid for any follow-up create-revision call

Example fix

// before
$params = array(
  'raw_diff' => $diff_text, // wrong key: server expects 'diff'
);

// after
$params = array(
  'diff' => $diff_text, // non-empty unified diff
);

if (!isset($params['diff']) || !is_string($params['diff'])
    || strlen(trim($params['diff'])) === 0) {
  throw new InvalidArgumentException(
    'createrawdiff requires non-empty diff text under key "diff"');
}

try {
  $result = $client->callMethodSynchronous('differential.createrawdiff', $params);
} catch (ConduitClientException $ex) {
  if (strpos($ex->getMessage(), 'must be non-empty') !== false) {
    // payload bug: the diff text is missing/empty - fix generation, do not retry
    throw new RuntimeException('Empty raw diff', 0, $ex);
  }
  throw $ex;
}

When it happens

Trigger: Sending no 'diff' key, an empty string, or a value under a differently named key (for example literally 'raw_diff') because the error message's field name misled the caller.

Common situations: Scripts that read the diff from stdin or a file that turned out empty; parameter names copied from the exception text instead of the API spec; pipelines where the diff-producing step failed silently upstream.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

• Field "changes" must be non-empty.
• ERR-BAD-DIFF
• ERR-NEED-DIFF
• ERR-NEED-FILE
• The raw diff you have submitted is too large to parse (it af

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/243eca8f2703ca0b. Report an issue: GitHub.