anchor.diff:  { stdenv, fetchFromGitHub, fetchpatch
   , meson, ninja, pkgconfig, sphinx
   , acl, curl, fuse, libselinux, udev, xz, zstd
  +, fuseSupport ? true
  +, selinuxSupport ? true
  +, udevSupport ? true
   , glibcLocales, rsync
   }:
   
  
positive.code:     sha256 = "0zx6zvj5a6rr3w9s207rvpfw7gwssiqmp1p3c75bsirmz4nmsdf0";
    };
  
    buildInputs = [ acl curl fuse libselinux udev xz zstd ];
    nativeBuildInputs = [ meson ninja pkgconfig sphinx ];
    checkInputs = [ glibcLocales rsync ];
  
  
negative.code:   '';
  
    PKG_CONFIG_UDEV_UDEVDIR = "lib/udev";
    mesonFlags = stdenv.lib.optionals (!fuseSupport) [ "-Dfuse=false" ]
                 ++ stdenv.lib.optionals (!udevSupport) [ "-Dudev=false" ]
                 ++ stdenv.lib.optionals (!selinuxSupport) [ "-Dselinux=false" ];
  
    doCheck = true;
    preCheck = ''
  