GKT3 does not have 'image-missing.png' packaged on MacOS which can lead to crashes
There is a GTK bug probably confirmed by the answers in gtk#3526 and code comments, that shows that applications will crash if there is a missing icon on MacOS and sometimes other linux platforms (example this report on linux: #7335 (closed)).
It appears GTK devs won't consider it possible (as they have closed the above issue) even though it is clearly happening in Gimp. This issue is a placeholder for finding the core issue and possibly providing a fix. By having a patch to show, it can be contributed to GTK.
As recommended by @Jehan.
See also #7319 (closed).