stunnel: Multiple outputs, parallel building

pkgs/tools/networking/stunnel/default.nix

@@ -8,6 +8,8 @@ stdenv.mkDerivation rec {
   pname = "stunnel";
   version = "5.67";
 
+  outputs = [ "out" "doc" "man" ];
+
   src = fetchurl {
     url    = "https://www.stunnel.org/archive/${lib.versions.major version}.x/${pname}-${version}.tar.gz";
     sha256 = "3086939ee6407516c59b0ba3fbf555338f9d52f459bcab6337c0f00e91ea8456";
@@ -15,6 +17,8 @@ stdenv.mkDerivation rec {
     # not the output of `nix-prefetch-url`
   };
 
+  enableParallelBuilding = true;
+
   buildInputs = [
     openssl
   ] ++ lib.optionals systemdSupport [