if {$isClient} then {
      set persistentDirectory $clientDirectory
    } else {
      verifyPersistentRootDirectory
      set persistentDirectory $persistentRootDirectory
    }

    set fileNamesOnly [list VERSION pkgIndex.eagle pkgIndex.tcl]

    foreach fileNameOnly $fileNamesOnly {
      set fileName [file join $packageName $fileNameOnly]
      set downloadFileName [file join $temporaryDirectory $fileName]

      file mkdir [file dirname $downloadFileName]

      if {[catch {
        downloadOneFile $language $version $platform \
            $fileName $downloadFileName $usePgp
      }] == 0} then {
        if {$usePgp} then {
          downloadOneFile $language $version $platform \
              [appendArgs $fileName .asc] \
              [appendArgs $downloadFileName .asc] $usePgp
        }

        set localFileName [file join $persistentDirectory $fileName]

        set compare [package vcompare \
            [extractVersionFromFile $downloadFileName] \
            [extractVersionFromFile $localFileName]]

        if {[isEagle]} then {
          file delete -recursive -- $temporaryDirectory
        } else {
          file delete -force -- $temporaryDirectory
        }

        return [expr {$compare > 0}]
      }
    }

    error "could not check higher version: no supported file names"
  }

  #
  # NOTE: This procedure attempts to guess a package name based on a list of
  #       its files.  It relies upon the fact that all packages must include
  #       a package index file.  The language argument must be one of the
  #       literal strings "eagle", "tcl", or "client".  The fileNames argument