server: Print a trace when sending a signal to a thread.
diff --git a/server/mach.c b/server/mach.c
index ec121e2..111953c 100644
--- a/server/mach.c
+++ b/server/mach.c
@@ -243,6 +243,8 @@
             thread->unix_tid = -1;
         }
     }
+    if (debug_level && ret != -1)
+        fprintf( stderr, "%04x: *sent signal* signal=%d\n", thread->id, sig );
     return (ret != -1);
 }