}

    #
    # NOTE: The regular expression pattern used when attempting to verify
    #       that OpenPGP is installed locally.  This must be configured
    #       according to the implementation of OpenPGP in use.
    #
    variable openPgpInstalledPattern; # DEFAULT: ^gpg \(GnuPG\) 2\.0\.
    variable openPgpInstalledPattern; # DEFAULT: ^gpg \(GnuPG\) 2\.[01]\.

    if {![info exists openPgpInstalledPattern]} then {
      set openPgpInstalledPattern {^gpg \(GnuPG\) 2\.0\.}
      set openPgpInstalledPattern {^gpg \(GnuPG\) 2\.[01]\.}
    }

    #
    # NOTE: The command to use when verifying OpenPGP signatures for the
    #       downloaded package scripts.  This must be configured according
    #       to the implementation of OpenPGP in use.
    #

    # NOTE: This procedure was stolen from the "getEagle.tcl" script.  It is
    #       designed to process a single HTTP request, including any HTTP
    #       3XX redirects (up to the specified limit), and return the raw
    #       HTTP response data.  It may raise any number of script errors.
    #
    # <public>
    proc getFileViaHttp { uri redirectLimit channel quiet args } {
      #
      # NOTE: This global variable is used to check the running version of
      #       Tcl.
      #
      global tcl_version

      #
      # NOTE: This variable is used to determine if plain HTTP URIs should be
      #       converted to HTTPS, if the "tls" package is available.
      #
      variable forceSecureUri

      #

      variable afterForPageProgress

      #
      # NOTE: This procedure requires the modern version of the HTTP package,
      #       which is typically included with the Tcl core distribution.
      #
      package require http 2.0

      #
      # NOTE: Tcl 8.6 added support for IPv6; however, on some machines this
      #       support can cause sockets to hang for a long time.  Therefore,
      #       for now, always force the use of IPv4.
      #
      if {[info exists tcl_version] && $tcl_version >= 8.6} then {
        namespace eval ::tcl::unsupported {}
        set ::tcl::unsupported::socketAF inet
      }

      #
      # NOTE: If the 'tls' package is available, always attempt to use HTTPS;
      #       otherwise, only attempt to use HTTP if explicitly allowed.
      #
      if {[catch {package require tls}] == 0} then {
        ::http::register https 443 [list ::tls::socket -tls1 true]