I'm getting that usual spammed error message from latest git -

ERR<26567>:evas_main lib/evas/canvas/evas_object_smart.c:911 _evas_object_smart_need_recalculate_set() Object 0x80000017a00000be is not stable during recalc loop

After poking around, I tracked it to lack of icons in elm_toolbar_item_append() calls. Leave out one icon, you get three errors. Leave out a bunch, you get a lot. An icon on every item, no errors.

It would help to track down these constant spammy messages if they gave some clue which object is having the issues, I mean they are smart objects apparently, they should be able to figure that out.