message: Always initialize Trace
  Summary: For convenience, `TRACE(X, 0, ...)` should work without `TRACE=...`.
diff: @@ -45,6 +45,7 @@ struct Tracer {
  const char* show_tracemodule = getenv("SHOW_TRACEMODULE");
  m_method_filter = getenv("TRACE_METHOD_FILTER");
  if (!traceenv) {
  + init_trace_file(nullptr);
  return;
  }
  