refcounting fix

src/runtime/builtin_modules/builtins.cpp

@@ -2182,7 +2182,8 @@ void setupBuiltins() {
         { "print", (PyCFunction)builtin_print, METH_VARARGS | METH_KEYWORDS, print_doc },
     };
     for (auto& md : builtin_methods) {
-        builtins_module->giveAttr(md.ml_name, new BoxedCApiFunction(&md, builtins_module, boxString("__builtin__")));
+        builtins_module->giveAttr(md.ml_name,
+                                  new BoxedCApiFunction(&md, builtins_module, autoDecref(boxString("__builtin__"))));
     }
 }
 }

src/runtime/builtin_modules/sys.cpp

@@ -744,8 +744,9 @@ void setupSys() {
 
     sys_flags_cls->freeze();
 
+    auto sys_str = getStaticString("sys");
     for (auto& md : sys_methods) {
-        sys_module->giveAttr(md.ml_name, new BoxedCApiFunction(&md, sys_module, boxString("sys")));
+        sys_module->giveAttr(md.ml_name, new BoxedCApiFunction(&md, sys_module, sys_str));
     }
 
     sys_module->giveAttrBorrowed("__displayhook__", sys_module->getattr(autoDecref(internStringMortal("displayhook"))));