Sam Van Campenhout

I did some testing and it's not only the `on` modifier that has this problem. It seems that all helpers and modifiers that come from Glimmer don't work with the...

I found the following in the [RFC](https://emberjs.github.io/rfcs/0432-contextual-helpers.html#the-helper-and-modifier-helpers): > Some built-in helpers or modifiers may not be resolvable with the helper and modifier helpers. For example, (helper "debugger") and (helper "yield")...

They are defined as class methods on the [`String` class](https://api.emberjs.com/ember/4.3/classes/String) so you have to click the String class to see them. After looking at [some other functions](https://github.com/emberjs/ember.js/blob/d2ad3bc47114eed0150e1208ce8c86266946f330/packages/%40ember/-internals/owner/index.ts#L81-L82) in the API...

I gave your reproduction a try and I think the problem is that a plain function is used as the modifier value which won't work without your default modifier manager...

I think the issue is caused by the Ember Inspector. Can you try disabling the extension and see if the deprecations are still shown? I opened an issue in the...

I did some sleuthing and I think I figured out the issue. The `Element` class has a [`prefix` property](https://developer.mozilla.org/en-US/docs/Web/API/Element/prefix) which is read-only, but since we're trying to set an attribute...

I still think that `prefix` is one of those 'spec outliers' for which `preferAttr` should return `true`. `form` is also handled by `preferAttr` and it's the exact same situation where...

I think this also means that the [`routes-segments-snake-case rule`](https://github.com/ember-cli/eslint-plugin-ember/blob/master/docs/rules/routes-segments-snake-case.md) can be removed from the recommended ruleset? I've been disabling that rule on every project I work on since we don't...

I _think_ we can simply remove these plugins as they are part of preset-env v7.14+ (and we list [7.20 as a dependency](https://github.com/babel/ember-cli-babel/blob/73e421f8dbf16953f45aa6600a6eefa7563663de/package.json#L54)): #501

While I like the idea of this rule, I don't think this issue is limited to the Ember ecosystem alone? Would it make sense to try to upstream it to...