anchor.diff:  
         # 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
  
positive.code:       "--enable-debug"
        (lib.optionalString enableSystemd "--with-systemd")
        (if stdenv.isDarwin then "--with-uuid=e2fs" else "--with-ossp-uuid")
      ] ++ lib.optionals icuEnabled [ "--with-icu" ];
  
      patches =
        [ (if atLeast "9.4" then ./patches/disable-resolve_symlinks-94.patch else ./patches/disable-resolve_symlinks.patch)
  
negative.code:       [ zlib readline openssl libxml2 ]
        ++ lib.optionals icuEnabled [ icu ]
        ++ lib.optionals enableSystemd [ systemd ]
        ++ lib.optionals gssSupport [ libkrb5 ]
        ++ lib.optionals (!stdenv.isDarwin) [ libossp_uuid ];
  
      nativeBuildInputs = [ makeWrapper ] ++ lib.optionals icuEnabled [ pkg-config ];
  