Bug: Page template dropdown disappeared after upgrading to Acorn v3.x

Terms

• I have read the guidelines for Contributing to Roots Projects
• This request is not a duplicate of an existing issue
• I have read the docs and followed them (if applicable)
• I have seached the Roots Discourse for answers and followed them (if applicable)
• This is not a personal support request that should be posted on the Roots Discourse community

Description

What’s wrong?

After upgrading Acorn to the 3.0.0-alpha.3 version (but it also happens on alpha.1 & alpha.2), the Template dropdown in the Page attributes metabox has completely disappeared somehow. When viewing my template sin the frontend I get a Target class [sage.view] does not exist. error?

What have you tried?

• I tried installing all 3.0.0-alpha versions and running all of these commands afterwards:

wp acorn acorn:init
wp acorn package:discover
wp acorn vendor:publish
wp acorn config:clear
wp acorn optimize:clear
wp acorn optimize
wp acorn view:cache

All without errors and I can also see my log1x/acf-composer fields & log1x/poet types in the backend.

• I disabled all of my plugins.
• I disabled all of my wordpress actions/filters in my theme.

What insights have you gained?

I think Acorn possible is not recognising my template files inside the resources/views folder even though get_theme_file_path('/resources/views') is returning the correct path?

Possible solutions

Downgrading to Acorn 2.1, but then I’m bumping into this bug again.

Temporary workarounds

Switch to a default Wordpress theme

Steps To Reproduce

1. Install roots/acorn 3.0.0-alpha.3 with composer in your Bedrock folder: composer require roots/acorn:3.0.0-alpha.3
2. Call the bootloader in your functions.php: \Roots\bootloader()->boot();
3. Go to an edit page in your Wordpress backend and have a look at the Page attributes box in the right sidebar.
4. Switch to a default Wordpress theme and repeat step 3.

Expected Behavior

The Page attributes box in the right sidebar should have a Template dropdown.

Actual Behavior

The Page attributes box in the right sidebar does not have a Template dropdown anymore.

Relevant Log Output

No php errors whatsoever

Versions

Acorn 3.0.0-alpha.3 PHP 8.0.22 Composer version 2.4.1

[felly]

I had the same Target class [sage.view] does not exist. error. I forgot to call the parent’s register()/boot() methods.

Here is my working ThemeServiceProvider:

<?php

namespace App\Providers;

use Roots\Acorn\Sage\SageServiceProvider;

class ThemeServiceProvider extends SageServiceProvider
{
    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        parent::register();
    }

    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        parent::boot();
    }
}

[Twansparant]

Did you notice it moved from page attributes to it’s own separate template panel?

Yeah I did notice that, but only if you have enabled Gutenberg, which I haven’t for this theme.