flutter: Generate target PKG_CONFIG_PATH at build time

  ];

  # Nix-specific compiler configuration.

  pkgConfigDirectories = builtins.filter builtins.pathExists (builtins.concatMap (pkg: map (dir: "${lib.getOutput "dev" pkg}/${dir}/pkgconfig") [ "lib" "share" ]) (appBuildDeps ++ extraPkgConfigPackages));

  pkgConfigPackages = map (lib.getOutput "dev") (appBuildDeps ++ extraPkgConfigPackages);

  includeFlags = map (pkg: "-isystem ${lib.getOutput "dev" pkg}/include") (appStaticBuildDeps ++ extraIncludes);

  linkerFlags = (map (pkg: "-rpath,${lib.getOutput "lib" pkg}/lib") appRuntimeDeps) ++ extraLinkerFlags;

in

  inherit (flutter) meta;

} ''

  for path in ${builtins.concatStringsSep " " (builtins.foldl' (paths: pkg: paths ++ (map (directory: "'${pkg}/${directory}/pkgconfig'") ["lib" "share"])) [ ] pkgConfigPackages)}; do

    addToSearchPath FLUTTER_PKG_CONFIG_PATH "$path"

  done

  mkdir -p $out/bin

  makeWrapper '${immutableFlutter}' $out/bin/flutter \

    --set-default ANDROID_EMULATOR_USE_SYSTEM_LIBS 1 \

    --prefix PATH : '${lib.makeBinPath (tools ++ buildTools)}' \

    --prefix PKG_CONFIG_PATH : '${builtins.concatStringsSep ":" pkgConfigDirectories}' \

    --prefix PKG_CONFIG_PATH : "$FLUTTER_PKG_CONFIG_PATH" \

    --prefix LIBRARY_PATH : '${lib.makeLibraryPath appStaticBuildDeps}' \

    --prefix CXXFLAGS "''\t" '${builtins.concatStringsSep " " (includeFlags ++ extraCxxFlags)}' \

    --prefix CFLAGS "''\t" '${builtins.concatStringsSep " " (includeFlags ++ extraCFlags)}' \