const pr_match_groups = context.payload.head_commit.message.match(/\Rollback of PR #(\d+).*/) || [];
  if (pr_match_groups.length != 2) {
    console.log(`PR Number not found in ${context.payload.head_commit.message}`);
    throw "Error extracting PR Number from commit message";
  }
  const pr_number = parseInt(pr_match_groups[1]);
  const owner = context.payload.repository.owner.name;
  const repo = context.payload.repository.name;