#
    variable fossilInfoCommand; # DEFAULT: fossil info ...

    if {![info exists fossilInfoCommand]} then {
      set fossilInfoCommand {fossil info --chdir {${directory}}}
    }

    #
    # NOTE: The regular expression pattern used when attempting to extract
    #       the current check-in identifier for the Fossil checkout.
    #
    variable fossilInfoCheckoutPattern; # DEFAULT: {^checkout:\s+... UTC$}

    if {![info exists fossilInfoCheckoutPattern]} then {
      set fossilInfoCheckoutPattern \
          {^checkout:\s+([0-9a-f]{40}) \d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2} UTC$}
    }

    #
    # NOTE: The regular expression pattern used when attempting to extract
    #       the root directory for the Fossil checkout.
    #
    variable fossilInfoLocalRootPattern; # DEFAULT: {^local-root:\s+(.*?)$}

    if {![info exists fossilInfoLocalRootPattern]} then {

      return $result
    } else {
      error [appendArgs \
          "failed to submit package metadata: " $data]
    }
  }

  #
  # NOTE: This procedure attempts to query the identifier of the Fossil
  #       checkout.  There are no arguments.  An empty string is returned if
  #       the information cannot be determined.
  #
  proc getCheckoutId {} {
    variable fossilInfoCommand
    variable fossilInfoCheckoutPattern
    variable scriptDirectory

    fossilMustBeInstalled

    if {[isEagle]} then {
      set directory [::PackageRepository::formatExecArgument \
          $scriptDirectory]

      if {[catch {
        eval exec -nocarriagereturns -stdout output -stderr error \
            [subst $fossilInfoCommand]
      } result] == 0} then {
        set result [appendArgs $output $error]
      } else {
        return ""
      }
    } else {
      set directory $scriptDirectory

      if {[catch {
        eval exec [subst $fossilInfoCommand]
      } result]} then {
        return ""
      }
    }

    if {![info exists result] || ![regexp -line -- \
        $fossilInfoCheckoutPattern $result dummy match]} then {
      return ""
    }

    return [string trim $match]
  }

  #
  # NOTE: This procedure attempts to query the root directory of the Fossil
  #       checkout.  There are no arguments.  An empty string is returned if
  #       the information cannot be determined.
  #
  proc getCheckoutDirectory {} {
    variable fossilInfoCommand
    variable fossilInfoLocalRootPattern
    variable scriptDirectory

    fossilMustBeInstalled

        eval exec [subst $fossilInfoCommand]
      } result]} then {
        return ""
      }
    }

    if {![info exists result] || ![regexp -line -- \
        $fossilInfoLocalRootPattern $result dummy match]} then {
      return ""
    }

    return [string trim $match]
  }

  #
  # NOTE: This procedure builds a native path using the specified parts and
  #       returns it.  All arguments are considered to be parts of the path.
  #
  proc joinPath { args } {

    fossilMustBeInstalled
    verifyCheckoutDirectory

    set branch [appendArgs pkg_ $package _ $patchLevel]

    set comment [appendArgs \
        "Add package " $package " v" $patchLevel " for " $language \
        " v" $version " using client \[" [getCheckoutId] \].]

    if {[isEagle]} then {
      set directory [::PackageRepository::formatExecArgument \
          $checkoutDirectory]

      set branch [::PackageRepository::formatExecArgument $branch]
      set comment [::PackageRepository::formatExecArgument $comment]