return true
      }
    }

    return false
  }

  #
  # NOTE: This procedure attempts to import the OpenPGP keys contained in
  #       the specified (named) file.  Non-zero is only returned if the
  #       OpenPGP keys are imported successfully.  A script error should
  #       not be raised by this procedure.  The fileName argument must be
  #       the fully qualified path and file name of the OpenPGP key file
  #       to import.  This procedure is only intended to be used from the
  #       "pkgr_setup.eagle" tool script and may go away in later versions
  #       of this package.
  #
  # <internal>
  proc importOpenPgpKeyFile { fileName varName } {
    variable openPgpImportCommand
    variable openPgpImportPattern

    if {[string length $varName] > 0} then {
      upvar 1 $varName result
    }

    if {[isEagle]} then {
      set fileName [appendArgs \" $fileName \"]

      if {[catch {
        eval exec -nocarriagereturns -stdout output -stderr error \
            [subst $openPgpImportCommand]
      } result] == 0} then {
        set result [appendArgs $output $error]
      } else {
        return false
      }
    } else {
      if {[catch {
        eval exec [subst $openPgpImportCommand] 2>@1
      } result]} then {
        return false
      }
    }

    if {![info exists result] || \
        ![regexp -line -- $openPgpImportPattern $result]} then {
      return false
    }

    return true
  }

  #
  # NOTE: This procedure returns the prefix for fully qualified variable
  #       names that MAY be present in the global namespace.  There are
  #       no arguments.
  #
  proc getLookupVarNamePrefix {} {
    return ::pkgr_; # TODO: Make non-global?

      if {![isEagle] && \
          [llength [package versions Garuda]] > 0} then {
        set autoRequireGaruda true
      } else {
        set autoRequireGaruda false
      }
    }

    #
    # NOTE: The command to use when attempting to import an OpenPGP key
    #       file.  This must be configured according to the implementation
    #       of OpenPGP in use.
    #
    variable openPgpImportCommand; # DEFAULT: gpg2 --import

    if {![info exists openPgpImportCommand]} then {
      set openPgpImportCommand {gpg2 --import {${fileName}}}
    }

    #
    # NOTE: The regular expression pattern used when attempting to verify
    #       that OpenPGP successfully imported one or more keys.  This must
    #       be configured according to the implementation of OpenPGP in use.
    #
    variable openPgpImportPattern; # DEFAULT: ^gpg: Total number processed: 1$

    if {![info exists openPgpImportPattern]} then {
      set openPgpImportPattern {^gpg: Total number processed: 1$}
    }

    #
    # NOTE: The command to use when attempting to verify that OpenPGP is
    #       installed locally.  This must be configured according to the
    #       implementation of OpenPGP in use.
    #
    variable openPgpInstalledCommand; # DEFAULT: gpg2 --version