Classy theme deprecated

Hi @francoud , We can set base theme as false. Recently created themes are using base theme as false. If set to false, no base theme is being used. It is clearly mentioned in - Defining a theme with an .info.yml file → document.If you need this changes on info.yml file i will create a patch for that.

I am reviewing this patch #4.

The Patch #4 is applying and it is working as accepted.

I've got Bootstrap Business 8.x-1.0-beta5 on Drupal 9.5.11. If I change "classy" to "false" in bootstrap_business.info.yml, I lose a lot of css formatting. Why is that? And what can I do about it?

@Andrew Perriman
CSS formatting issue will be appearing due to base theme styles is inheriting in child theme.
So classy theme can download/install separately from https://www.drupal.org/project/classy → due to it classy is not part of core in new Drupal releases.

As outlined in the change record for the removal of classy,
There are a couple of options:
Option 1: use the Classy contributed theme
Option 2: Remove your theme's dependency on Stable themes altogether
https://www.drupal.org/node/3305674 →

To use the contrib version, there will need to be a dependency of classy:classy added to the info.yml and possibly an addition of a require to a composer.json file, to make sure the classy theme is enabled when this theme is enabled.

To remove the dependency, the preprocess functions, twig templates and libraries will need to be moved from the classy theme to this theme, so the inheritance is no longer needed.

Just removing the base theme entry will result in missing functionality and styling as reported in #8.

I just started with Option: 2, But I noticed that lots of work needs to be done.
So I will suggest using Option 1 which is suggesting to use the Classy contributed theme → as base theme.