#       here, because Eagle does not add a version argument when one is
  #       not explicitly supplied to the [package require] sub-command.
  #
  proc packageUnknownHandler { package {version ""} } {
    variable verboseUnknownResult

    #
    # NOTE: First, run our special [package unknown] handler.
    #
    set code(1) [catch {lookupPackage $package $version handler} result(1)]

    if {$verboseUnknownResult} then {
      pkgLog [appendArgs \
          "repository handler results for package \"" [formatPackageName \
          $package $version] "\" are " [formatResult $code(1) $result(1)]]
    }

  #       currently configured package repository server.  The package
  #       argument is the name of the package being sought, it cannot be an
  #       empty string.  The version argument must be a specific version -OR-
  #       a package specification that conforms to TIP #268.  The caller
  #       argument must be an empty string -OR- the literal string "handler".
  #
  # <public>
  proc lookupPackage { package version caller } {
    #
    # NOTE: Get the list of API keys and try each one, in order, until
    #       the package is found.
    #
    set apiKeys [getLookupApiKeys]; lappend apiKeys ""

    foreach apiKey $apiKeys {