anchor.diff:        "--enable-debug"
         (lib.optionalString enableSystemd "--with-systemd")
         (if stdenv.isDarwin then "--with-uuid=e2fs" else "--with-ossp-uuid")
  -    ] ++ lib.optionals icuEnabled [ "--with-icu" ];
  +    ] ++ lib.optionals icuEnabled [ "--with-icu" ]
  +      ++ lib.optionals gssSupport [ "--with-gssapi" ];
   
       patches =
         [ (if atLeast "9.4" then ./patches/disable-resolve_symlinks-94.patch else ./patches/disable-resolve_symlinks.patch)
  
positive.code:       [ zlib readline openssl libxml2 ]
        ++ lib.optionals icuEnabled [ icu ]
        ++ lib.optionals enableSystemd [ systemd ]
        ++ lib.optionals (!stdenv.isDarwin) [ libossp_uuid ];
  
      nativeBuildInputs = [ makeWrapper ] ++ lib.optionals icuEnabled [ pkg-config ];
  
negative.code: 
        # This is important to obtain a version of `libpq` that does not depend on systemd.
        , enableSystemd ? (lib.versionAtLeast version "9.6" && !stdenv.isDarwin)
        , gssSupport ? with stdenv.hostPlatform; !isWindows && !isStatic, libkrb5
  
  
        # for postgreql.pkgs
        , this, self, newScope, buildEnv
  