anchor.diff:  let
     inherit (stdenv)
       targetSystem;
  -  inherit (stdenv.lib)
  +  inherit (lib)
  +    boolEn
       elem
  -    enFlag
       optionals
       platforms;
   
  
positive.code:     "-fPIC"
    ];
  
    meta = with stdenv.lib; {
      description = "Library for Fast Discrete Fourier Transform";
      homepage = http://www.fftw.org/;
      license = licenses.gpl2Plus;
  
negative.code:     "--disable-avx512"
      "--disable-avx-128-fma"
      "--disable-kcvi"
      "--${boolEn (elem targetSystem platforms.powerpc-all)}-altivec"
      "--disable-vsx"
      "--${boolEn (elem targetSystem platforms.arm-all)}-neon"
      #--enable-armv8cyclecounter
      "--${boolEn (
        precision == "single"
        || precision == "double")}-generic-simd128"
      "--${boolEn (
        precision == "single"
        || precision == "double")}-generic-simd256"
      #--enable-mips-zbus-timer
      "--enable-fma"
      #"--${boolEn (
      #  mpi != null
      #  && (
      #    precision == "single"
      #    || precision == "double"
      #    || precision == "long-double"))}-mpi"  null)
      "--disable-fortran"
      "--enable-openmp"
      "--enable-threads"
  