anchor.diff:      "--disable-gtk-doc"
       "--disable-gtk-doc-html"
       "--disable-gtk-doc-pdf"
  -    (enFlag "introspection" (gobject-introspection != null) null)
  +    "--${boolEn (gobject-introspection != null)}-introspection"
       "--enable-libgeoclue"
  -    (enFlag "3g-source" (modemmanager != null) null)
  -    (enFlag "cdma-source" (modemmanager != null) null)
  -    (enFlag "modem-gps-source" (modemmanager != null) null)
  -    (enFlag "nmea-source" (avahi != null) null)
  +    "--${boolEn (modemmanager != null)}-3g-source"
  +    "--${boolEn (modemmanager != null)}-cdma-source"
  +    "--${boolEn (modemmanager != null)}-modem-gps-source"
  +    "--${boolEn (avahi != null)}-nmea-source"
       "--enable-backend"
       "--disable-demo-agent"
       "--enable-compile-warnings"
  
positive.code: }:
  
  let
    inherit (stdenv.lib)
      enFlag;
  
    versionMajor = "2.4";
    version = "${versionMajor}.4";
  in
  stdenv.mkDerivation rec {
    name = "geoclue-${version}";
  
negative.code:   src = fetchurl {
      url = "https://www.freedesktop.org/software/geoclue/releases/"
        + "${versionMajor}/${name}.tar.xz";
      sha256 = "c57df7455c9b4b2f43b0f5d9be14d52f5ff9897236df768f6ca9044b79b6d3b6";
    };
  
    nativeBuildInputs = [
  