forms – Implementing hook_entity_type_build causes 500 error on cache clear

I recently attempted to display custom form modes based on the currently logged in user. My searching led me to implement hook_entity_type_build. However, I am finding that even just having this function declared with an empty body is causing an internal 500 error whenever I clear the cache using Devel > Cache Clear :

(Tue Sep 15 14:29:21.472533 2020) (php7:error) (pid 13440) (client address:port) PHP Fatal error:  Allowed memory size of 536870912 bytes exhausted (tried to allocate 65536 bytes) in /path/to/drupal/core/includes/ on line 62, referer:

My module has a couple other hooks implemented, but I’ve verified that adding / removing this empty function body to myModule.module directly causes / removes the crashes:

function myModule_entity_type_build(array &$entity_types){
      #causes crashes just by existing!

I’m still developing the site so it barely has any content on it at all… What in the world could cause an empty hook declaration to use so much memory (~500MB) on cache clear?? Any advice on where to look next is greatly appreciated!