_fetchPackageInfo = async function(packageName) {
  logger.info({ pkg: packageName }, "_fetchPackageInfo");
  try {
    const pkgMeta = await fetchPackageMeta(packageName);
    const version = pkgMeta["dist-tags"].latest;
    const versionInfo = pkgMeta.versions[version];
    // Save the unity version.
    const unityVersion = /^[0-9]{4,4}\.[0-9]/i.test(versionInfo.unity)
      ? versionInfo.unity
      : "";
    await PackageExtra.setUnityVersion(packageName, unityVersion);
    // Save the update time.
    const timeStr = pkgMeta.time[version] || 0;
    const time = new Date(timeStr).getTime();
    await PackageExtra.setUpdatedTime(packageName, time);
    // Save the package version.
    await PackageExtra.setVersion(packageName, version);
  } catch (error) {
    logger.error(
      httpErrorInfo(error, { pkg: packageName }),
      "fetch package info error"
    );
  }
}
Fetch package info from the registry.
@param {string} packageName