Installation on TYPO3 11.5.36 installed styleguide extension 12.0.5

[medarob]

I created a new TYPO3 11.5.36 installation and only wanted to install the styleguide extension.

Executing the composer command installed version 12 of the styleguide extension, which is only compatible with TYPO3 12

The styleguide icon in the help section was missing. There was no way to create the pages in the backend and via the command line I got the following error

bash-4.2$ vendor/bin/typo3 styleguide:generate -c

In ErrorHandler.php line 137:
                                                                                                                                                                                                        
  PHP Warning: Undefined array key "tx_styleguide_ctrl_common" in /var/www/typo3_cms-styleguide/public/typo3conf/ext/styleguide/Classes/TcaDataGenerator/TableHandler/AbstractTableHandler.php line 70

Downgrading the Stylguide Extension to version 11 helped.
The Styleguide Icon was now available in the helpsection.

[lolli42]

Hey.
styleguide in v11 and v12 needs to be aligned to the specific core verison, see the readme.md of the according styleguide branches:

composer require --dev typo3/cms-styleguide:^11

This has been resolved with v13 where styleguide is merged to core monorepo, but projects based on v11 and v12 core need to have this explicit version constraint when requiring styleguide.