--- vm_trace.c.orig 2015-11-08 14:49:09 UTC +++ vm_trace.c @@ -390,7 +390,7 @@ rb_suppress_tracing(VALUE (*func)(VALUE) volatile int raised; volatile int outer_state; VALUE result = Qnil; - rb_thread_t *th = GET_THREAD(); + rb_thread_t *volatile th = GET_THREAD(); int state; const int tracing = th->trace_arg ? 1 : 0; rb_trace_arg_t dummy_trace_arg;