anchor.diff: -{ lib, stdenv, fetchFromGitHub
  -, meson, ninja, pkg-config, python3, sphinx
  -, acl, curl, fuse, libselinux, udev, xz, zstd
  +{ lib
  +, stdenv
  +, fetchFromGitHub
  +, meson
  +, ninja
  +, pkg-config
  +, python3
  +, sphinx
  +, acl
  +, curl
  +, fuse
  +, libselinux
  +, udev
  +, xz
  +, zstd
   , fuseSupport ? true
   , selinuxSupport ? true
   , udevSupport ? true
  -, glibcLocales, rsync
  +, glibcLocales
  +, rsync
   }:
   
   stdenv.mkDerivation {
  
positive.code: 
    meta = with lib; {
      description = "Content-Addressable Data Synchronizer";
      homepage    = "https://github.com/systemd/casync";
      license     = licenses.lgpl21;
      platforms   = platforms.linux;
      maintainers = with maintainers; [ flokli ];
    };
  }
  
negative.code:   };
  
    buildInputs = [ acl curl xz zstd ]
      ++ lib.optionals (fuseSupport) [ fuse ]
      ++ lib.optionals (selinuxSupport) [ libselinux ]
      ++ lib.optionals (udevSupport) [ udev ];
    nativeBuildInputs = [ meson ninja pkg-config python3 sphinx ];
    checkInputs = [ glibcLocales rsync ];
  
  