#       did we just download an OpenPGP signature file?
    #
    if {$usePgp && [isOpenPgpSignatureFileName $localFileName true]} then {
      #
      # NOTE: Attempt to verify the OpenPGP signature.  If this fails,
      #       an error is raised.
      #
      ::PackageRepository::probeForOpenPgpInstallation
      ::PackageRepository::openPgpMustBeInstalled

      if {![::PackageRepository::verifyOpenPgpSignature $localFileName]} then {
        error [appendArgs \
            "bad OpenPGP signature \"" $localFileName \"]
      }
    }