drawterm: fix audio using padsp

drawterm uses an oss audio backend by default for CONF=unix.
The easiest way I've seen to get this working for most systems is
to wrap it with padsp.

pkgs/tools/admin/drawterm/default.nix

@@ -2,6 +2,7 @@
 , lib
 , fetchgit
 , installShellFiles
+, makeWrapper
 , xorg
 , pkg-config
 , wayland-scanner
@@ -10,6 +11,7 @@
 , wayland-protocols
 , libxkbcommon
 , wlr-protocols
+, pulseaudio
 , config
 }:
 
@@ -25,10 +27,9 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ installShellFiles ] ++ {
     linux = [ pkg-config wayland-scanner ];
-    unix = [];
+    unix = [ makeWrapper ];
   }."${config}" or (throw "unsupported CONF");
 
-
   buildInputs = {
     linux = [ pipewire wayland wayland-protocols libxkbcommon wlr-protocols ];
     unix = [ xorg.libX11 xorg.libXt ];
@@ -37,11 +38,21 @@ stdenv.mkDerivation rec {
   # TODO: macos
   makeFlags = [ "CONF=${config}" ];
 
-  installPhase = ''
+  installPhase = {
+    linux = ''
       install -Dm755 -t $out/bin/ drawterm
+    '';
+    unix = ''
+      # wrapping the oss output with pulse seems to be the easiest
+      mv drawterm drawterm.bin
+      install -Dm755 -t $out/bin/ drawterm.bin
+      makeWrapper ${pulseaudio}/bin/padsp $out/bin/drawterm --add-flags $out/bin/drawterm.bin
+     '';
+  }."${config}" or (throw "unsupported CONF")  + ''
       installManPage drawterm.1
   '';
 
+
   meta = with lib; {
     description = "Connect to Plan 9 CPU servers from other operating systems.";
     homepage = "https://drawterm.9front.org/";