api.modifyClass sometimes(!) not working

[david (David Taylor)]

I’ve just improved our warning for this kind of situation:

DEV: Improve modifyClass warning message

and also written up this documentation which explains the cause and how to resolve it:

Using modifyClass for objects which are initialized early in boot

When using modifyClass in an initializer, you may see this warning in the console: (type) has already been initialized and registered as a singleton. Move the modifyClass call earlier in the boot process (e.g. to a pre-initializer) for changes to take effect. (Prior to April 2022, the error text “(type) was already cached in the container. Changes won’t be applied.”) This commonly happens when overriding methods on services (e.g. topicTrackingState), and on models which are initialized earl…

I think that should take care of all the concerns in this topic. If not, please share some example failing code and I’ll take a look.