check `ARY_SHARED_ROOT_P()`.

ARY_SHARED_ROOT_P(ary) is true, ARY_HEAP_CAPA(ary) should not
be called.

array.c

@@ -786,7 +786,11 @@ void
 rb_ary_free(VALUE ary)
 {
     if (ARY_OWNS_HEAP_P(ary)) {
-        (void)RB_DEBUG_COUNTER_INC_IF(obj_ary_extracapa, ARY_HEAP_CAPA(ary) > RARRAY_LEN(ary));
+        if (USE_DEBUG_COUNTER &&
+            !ARY_SHARED_ROOT_P(ary) &&
+            ARY_HEAP_CAPA(ary) > RARRAY_LEN(ary)) {
+            RB_DEBUG_COUNTER_INC(obj_ary_extracapa);
+        }
 
         if (RARRAY_TRANSIENT_P(ary)) {
             RB_DEBUG_COUNTER_INC(obj_ary_transient);