Magento 2.4 fails to install due to missing composer config file in composer_home

I tried to install Magento 2.4 via command line. It runs smooth until

[Progress: 653 / 1206] Module 'Magento_ComposerRootUpdatePlugin': 

At this step the installation fails with

Installing data... Reading /<magento_root>/composer.json Loading config file /<magento_root>/composer.json Failed to initialize global composer: Composer could not find the config file: /<magento_root>/var/composer_home/composer.json To initialize a project, please create a composer.json file as described in the "Getting Started" section 

Composer is installed globally. The Magento documentation does not mention anything else regarding composer.

Thank you very much.

For reference: I also posted at stackexchange. People seem to face the same issue but no solution so far:

submitted by /u/hardy123480
[link] [comments]