Use parti_commandtrace() to set trace func, not ppui.cmdtrace.

src/nethack.cc

@@ -157,11 +157,11 @@ static void netupdate() {
     netupdates = 0;
     if(netsin.sin_addr.s_addr == INADDR_ANY) {
 	ppui.drawtrace = NULL;
-	ppui.cmdtrace = NULL;
+	parti_cmdtrace( NULL );
  	return;
     }
     ppui.drawtrace = broadcasting.jumps ? navtrace : NULL;
-    ppui.cmdtrace = broadcasting.cmds ? cmdtrace : NULL;
+    parti_cmdtrace( broadcasting.cmds ? cmdtrace : NULL );
 }
 
 void aer2rxyz( float rxyz[3], const float aer[3] ) {