anchor.diff:    src = fetchFromGitHub {
       owner = "intel";
       repo = "opa-psm2";
  -    rev = "IFS_RELEASE_${ifs_version}";
  -    sha256 = "0ckrfzih1ga9yvximxjdh0z05kn9l858ykqiblv18w6ka3gra1xz";
  +    rev = "PSM2_${version}";
  +    sha256 = "062hg4r6gz7pla9df70nqs5i2a3mp1wszmp4l0g771fykhhrxsjg";
     };
   
     postInstall = ''
  
positive.code: 
    buildInputs = [ numactl pkgconfig ];
  
    installFlags = [ 
      "DESTDIR=$(out)"
      "UDEVDIR=/etc/udev"
      "LIBPSM2_COMPAT_CONF_DIR=/etc"
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "libpsm2";
    version = "11.2.185";
  
    preConfigure= ''
      export UDEVDIR=$out/etc/udev
  