Can't compile style for custom theme which inherits from another custom theme

[Eddcapone]

Preconditions and environment

• 2.4.4
• OS: Ubuntu 20.04.2 LTS
• Magento is in developer mode
• Grunt installed

Code:

issue_35684.zip (extract to root dir of the magento project)

Steps to reproduce

Overview

1. Create Theme Foo (inheriting from Magento/luma)
2. Create Theme Bar (inheriting from Foo)
3. Create Module Company_Test
4. Setup Upgrade
5. Grunt configuration
6. Grunt Refresh

1. Create Theme Foo (inheriting from Magento/luma)

1.1 app/design/frontend/company/foo/registration.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

use \Magento\Framework\Component\ComponentRegistrar;

ComponentRegistrar::register(ComponentRegistrar::THEME, 'frontend/company/foo', __DIR__);

1.2 app/design/frontend/company/foo/theme.xml

<theme xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:noNamespaceSchemaLocation="urn:magento:framework:Config/etc/theme.xsd">
    <title>Foo</title>
    <parent>Magento/luma</parent>
</theme>

1.3 app/design/frontend/company/foo/web/css/source/_extend.less

@import '_mixin.less';

1.4 app/design/frontend/company/foo/web/css/source/_mixin.less

.h1 {
    color: red;
    font-size: 24px;
}

2. Create Theme Bar (inheriting from Foo)

2.1 app/design/frontend/company/bar/registration.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

use \Magento\Framework\Component\ComponentRegistrar;

ComponentRegistrar::register(ComponentRegistrar::THEME, 'frontend/company/bar', __DIR__);

2.2 app/design/frontend/company/bar/theme.xml

<theme xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:noNamespaceSchemaLocation="urn:magento:framework:Config/etc/theme.xsd">
    <title>Bar</title>
    <parent>company/foo</parent>
</theme>

2.3 app/design/frontend/company/bar/web/css/source/_extend.less

@import '_text.less';

2.4 app/design/frontend/company/bar/web/css/source/_text.less

.black { color: black; }

3. Create Module Company_Test

3.1 app/code/Company/Test/registration.php

<?php
\Magento\Framework\Component\ComponentRegistrar::register(
    \Magento\Framework\Component\ComponentRegistrar::MODULE,
    'Company_Test',
    __DIR__
);

3.2 app/code/Company/Test/etc/module.xml

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
	<module name="Company_Test" setup_version="1.0.0"/>
</config>

3.3 app/code/Company/Test/view/frontend/web/css/source/_module.less

body.contact-index-index {
    .page-title { .h1(); }
}

3.4 Enable Module "Company_Test"

php bin/magento module:enable Company_Test

4. Setup Upgrade

php bin/magento setup:upgrade

5. Grunt Configuration

dev/tools/grunt/configs/local-themes.js

/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

 'use strict';

 /**
  * Define Themes
  *
  * area: area, one of (frontend|adminhtml|doc),
  * name: theme name in format Vendor/theme-name,
  * locale: locale,
  * files: [
  * 'css/styles-m',
  * 'css/styles-l'
  * ],
  * dsl: dynamic stylesheet language (less|sass)
  *
  */
 module.exports = {
     company_foo: {
         area: 'frontend',
         name: 'company/foo',
         locale: 'de_DE',
         files: [
             'css/styles-m',
             'css/styles-l'
         ],
         dsl: 'less'
     },
     company_bar: {
         area: 'frontend',
         name: 'company/bar',
         locale: 'de_DE',
         files: [
             'css/styles-m',
             'css/styles-l'
         ],
         dsl: 'less'
     },
 };

6. Grunt Refresh

Run grunt refresh

Expected result

It should compile without an error.

Actual result

-> .h1 is undefined

user@xx-VirtualBox:/var/www/company/fresh_m244$ grunt refresh
Running "refresh" task

Running "clean:var" (clean) task
>> 1433 paths cleaned.

Running "clean:pub" (clean) task
>> 1194 paths cleaned.

Running "clean:styles" (clean) task
>> 0 paths cleaned.

Running "clean:markup" (clean) task
>> 0 paths cleaned.

Running "clean:js" (clean) task
>> 0 paths cleaned.

Running "clean:generation" (clean) task
>> 1732 paths cleaned.

Running "clean:company_foo" (clean) task
>> 0 paths cleaned.

Running "clean:company_bar" (clean) task
>> 0 paths cleaned.

Running "exec:all" (exec) task
grunt --force clean:company_foo
Processed Area: frontend, Locale: de_DE, Theme: company/foo, File type: less.
-> css/styles-m.less
-> css/styles-l.less
Successfully processed.
Running "clean:company_bar" (clean) task
>> 49 paths cleaned.

Done.


Execution Time (2022-07-22 11:58:46 UTC+2)
loading tasks      92ms  ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 68%
clean:company_bar  42ms  ▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 31%
Total 135ms

Processed Area: frontend, Locale: de_DE, Theme: company/bar, File type: less.
-> css/styles-m.less
-> css/styles-l.less
Successfully processed.

Running "less:company_foo" (less) task
>> 2 stylesheets created.
>> 2 sourcemaps created.

Running "less:company_bar" (less) task
>> pub/static/frontend/company/bar/de_DE/Company_Test/css/source/_module.less: [L2:C18] .h1 is undefined
Warning: Error compiling pub/static/frontend/company/bar/de_DE/css/styles-m.less Use --force to continue.

Aborted due to warnings.


Execution Time (2022-07-22 11:58:33 UTC+2)
clean:var         305ms  ▇▇ 1%
clean:pub         382ms  ▇▇ 1%
clean:generation  324ms  ▇▇ 1%
exec:all          21.8s  ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 80%
less:company_foo   3.8s  ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 14%
less:company_bar  478ms  ▇▇▇ 2%
Total 27.4s

Additional information

If I skip 2.3 and 2.4 then compilation works.

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant]

Hi @Eddcapone. Thank you for your report.
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• Steps to reproduce
• Expected and actual results

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[mrtuvn]

styles in module you will not get ability to use some default value than theme. From my experiences, current some value/variables can't call from module scope less. Write styles from module or theme not have much differences. Magento wrap all styles into final css output

[Eddcapone]

@mrtuvn Then how can I solve it? It looks like a magento bug to me.

[mrtuvn]

Just curious why not to use in theme scope/area in app/design

[mrtuvn]

You can try this approach (but this is custom module) not default function of magento
https://github.com/swissup/module-rtl#less-mixins

[Eddcapone]

Just curious why not to use in theme scope/area in app/design

Because it is only needed for the extension. If the extension is not active e.g. because it is only enabled for a certain store view, then the style is not needed. If I would put it in the theme, then it would load all the time.

[mrtuvn]

Oke make more senses to me!

[mrtuvn]

In your specific case you can import mixins in your module like this

_module.less

@import (reference) '_mixins';
// Other styles

_mixins you can use syntax like
https://github.com/magento/magento2/blob/2.4-develop/app/design/frontend/Magento/blank/web/css/source/_extends.less

@abs-yourmixins-name: {
    //Any code less/css here
};

.h1() {
 // Any code less/css here
}

[mrtuvn]

From my experiences from module scope (app/code/ or vendor/magento/ v.v)
you only use variables from magento lib/web/css
You can't get variables/mixins define in app/design

[Eddcapone]

From my experiences from module scope (app/code/ or vendor/magento/ v.v) you only use variables from magento lib/web/css You can't get variables/mixins define in app/design

Thats not true. I just tested it and it works. I defined a mixin in my theme and used it in the module successfully.

It just does not work if you create another theme which is a child theme of your first theme like described in my bug report.

[mrtuvn]

current my client used v2.3.3. I can't call mixins defined in child theme from module app/code. Got issue mixin undefined
I don't have instance test in higher version for re-test this case

[engcom-Echo]

Hello @Eddcapone,

We have tried to reproduce this issue on latest 2.4-develop branch but unable to reproduce and below are the steps which i have #35684.

1. Create Theme Foo (inheriting from Magento/luma)
2. Create Theme Bar (inheriting from Foo)
3. Create Module Company_Test
4. Setup Upgrade
5. Grunt configuration
6. Grunt Refresh

Please find the attached screen for your reference.

Please provide more information for this issue so that we can reproduce.

Thanks