xgboost: preserve cmake targets in install phase

    let libname = "libxgboost${stdenv.hostPlatform.extensions.sharedLibrary}";

    in ''

      runHook preInstall

      mkdir -p $out

      cp -r ../include $out

      cp -r ../dmlc-core/include/dmlc $out/include

      cp -r ../rabit/include/rabit $out/include

    '' + lib.optionalString (!rLibrary) ''

      install -Dm755 ../lib/${libname} $out/lib/${libname}

      install -Dm755 ../xgboost $out/bin/xgboost

    ''

    # the R library option builds a completely different binary xgboost.so instead of

    # libxgboost.so, which isn't full featured for python and CLI

    + lib.optionalString rLibrary ''

      mkdir $out/library

      mkdir -p $out/library

      export R_LIBS_SITE="$out/library:$R_LIBS_SITE''${R_LIBS_SITE:+:}"

      make install -l $out/library

    '' + ''

      cmake --install .

      cp -r ../rabit/include/rabit $out/include

      runHook postInstall

    '';