darkice: Fix build due to multiple outputs

pkgs/tools/audio/darkice/default.nix

···
-{ stdenv, buildEnv, fetchurl, alsaLib, faac, libjack2, lame, libogg, libopus, libpulseaudio, libsamplerate, libvorbis }:
+{ stdenv, buildEnv, fetchurl
+, libjack2, alsaLib, libpulseaudio
+, faac, lame, libogg, libopus, libvorbis, libsamplerate
+}:
 
 let
   oggEnv = buildEnv {
     name = "env-darkice-ogg";
     paths = [
-      libopus libvorbis libogg
+      libopus.dev libopus libvorbis.dev libvorbis libogg.dev libogg
+    ];
+  };
+
+  darkiceEnv = buildEnv {
+    name = "env-darkice";
+    paths = [
+      lame.out lame.lib libpulseaudio libpulseaudio.dev alsaLib alsaLib.dev libsamplerate.out libsamplerate.dev
     ];
   };
 
···
   };
 
   configureFlags = [
-    "--with-alsa-prefix=${alsaLib}"
+    "--with-alsa-prefix=${darkiceEnv}"
     "--with-faac-prefix=${faac}"
     "--with-jack-prefix=${libjack2}"
-    "--with-lame-prefix=${lame}"
+    "--with-lame-prefix=${darkiceEnv}"
     "--with-opus-prefix=${oggEnv}"
-    "--with-pulseaudio-prefix=${libpulseaudio}"
-    "--with-samplerate-prefix=${libsamplerate}"	
+    "--with-pulseaudio-prefix=${darkiceEnv}"
+    "--with-samplerate-prefix=${darkiceEnv}"
     "--with-vorbis-prefix=${oggEnv}"
 #    "--with-aacplus-prefix=${aacplus}" ### missing: aacplus
 #    "--with-twolame-prefix=${twolame}" ### missing: twolame
···
     homepage = http://darkice.org/;
     description = "Live audio streamer";
     license = stdenv.lib.licenses.gpl3;
-    maintainers = with stdenv.lib.maintainers; [ ikervagyok ];
+    maintainers = with stdenv.lib.maintainers; [ ikervagyok fpletz ];
   };
 }