TASKQ_DYNAMIC not yet support, do not create the global taskq with that flag or we crash with debug enabled. Also don't bother dumping debug when debugging is diabled, it's pointless

modules/spl/spl-debug.c

@@ -1118,8 +1118,10 @@ void spl_debug_bug(char *file, const char *func, const int line, int flags)
          if (spl_debug_panic_on_bug)
                 spl_panic_in_progress = 1;
 
+#ifdef DEBUG
         spl_debug_dumpstack(NULL);
         spl_debug_dumplog(flags);
+#endif
 
         if (spl_debug_panic_on_bug)
                 panic("SBUG");

modules/spl/spl-taskq.c

@@ -475,7 +475,7 @@ spl_taskq_init(void)
         ENTRY;
 
         system_taskq = taskq_create("system_taskq", 64, minclsyspri, 4, 512,
-                                    TASKQ_DYNAMIC | TASKQ_PREPOPULATE);
+                                    TASKQ_PREPOPULATE);
 	if (system_taskq == NULL)
 		RETURN(1);