phacility/phabricator · error · Exception

Commit "%s" is not an ancestor of any branch head, so it can

Error message

Commit "%s" is not an ancestor of any branch head, so it can not be built with Buildkite.

What it means

getBuildkiteBranch() (PhabricatorRepositoryCommit.php:741-769) runs diffusion.branchquery with 'contains' => commit identifier to find branch heads that contain the commit, then returns 'refs/heads/<branch>' for Buildkite. If no branch head has the commit as an ancestor, there is no ref Buildkite can build, so it throws.

Source

Thrown at src/applications/repository/storage/PhabricatorRepositoryCommit.php:759

  public function getBuildkiteBranch() {
    $viewer = PhabricatorUser::getOmnipotentUser();
    $repository = $this->getRepository();

    $branches = DiffusionQuery::callConduitWithDiffusionRequest(
      $viewer,
      DiffusionRequest::newFromDictionary(
        array(
          'repository' => $repository,
          'user' => $viewer,
        )),
      'diffusion.branchquery',
      array(
        'contains' => $this->getCommitIdentifier(),
        'repository' => $repository->getPHID(),
      ));

    if (!$branches) {
      throw new Exception(
        pht(
          'Commit "%s" is not an ancestor of any branch head, so it can not '.
          'be built with Buildkite.',
          $this->getCommitIdentifier()));
    }

    $branch = head($branches);

    return 'refs/heads/'.$branch['shortName'];
  }

  public function getBuildkiteCommit() {
    return $this->getCommitIdentifier();
  }


/* -(  PhabricatorCustomFieldInterface  )------------------------------------ */

View on GitHub (pinned to 5720a38cfe)

Solutions

1. Ensure the commit is pushed as (or merged into) a real branch head before the Buildkite step runs, e.g. publish the Diff or push the branch
2. Resync the mirror so the branch query sees current refs: bin/repository update / re-run discovery for the repository
3. Configure the build plan so the Buildkite step only runs on final (published) builds rather than draft builds

// Pre-flight: ask which branches contain the commit, mirroring the step.
$branches = DiffusionQuery::callConduitWithDiffusionRequest(
  PhabricatorUser::getOmnipotentUser(),
  DiffusionRequest::newFromDictionary(array(
    'repository' => $repository,
    'user' => PhabricatorUser::getOmnipotentUser(),
  )),
  'diffusion.branchquery',
  array(
    'contains' => $commit->getCommitIdentifier(),
    'repository' => $repository->getPHID(),
  ));
if (!$branches) {
  // not on any branch head: do not run the Buildkite step yet
}

function isOnBranchHead(
  PhabricatorRepository $repository,
  PhabricatorRepositoryCommit $commit) {
  // Cheap heuristic: tag-only or unpublished commits are risky; verify via
  // diffusion.branchquery 'contains' before building.
  return (bool)DiffusionBranchQuery::callConduitWithDiffusionRequest(
    null, null, 'diffusion.branchquery',
    array('contains' => $commit->getCommitIdentifier()));
}

try {
  $branch = $commit->getBuildkiteBranch();
} catch (Exception $ex) {
  // Commit not on any branch head (deleted branch, tag-only, unpublished
  // diff): fail the build target with the message; retry after the commit
  // is pushed to a branch.
  $build_target->log($ex->getMessage());
  throw new HarbormasterBuildFailureException();
}

When it happens

Trigger: A Buildkite build step runs on a buildable whose commit is reachable only from tags, pushed under refs/diff/* or another non-branch ref, on a branch deleted/force-pushed before the build executed, or not pushed to the remote at all (pre-publish draft builds).

Common situations: Building Differential patch/Diff branches that were never pushed as real branches; racing a force-push or branch deletion in a fast-moving mirror; tag-only release commits; stale mirrors whose refs have not been updated yet.

Related errors

• This commit ("%s") is associated with a hosted repository ("
• This commit ("%s") is associated with a repository ("%s") wh
• This object does not support builds with Buildkite.
• Unable to load API token ("%s")!
• Buildkite did not return a "%s"!

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/a60f0c8488f02a59. Report an issue: GitHub.