Composer require error: can't delete default.services.yml

In Drupal version 8.8.0, the permissions for sites/default are set to unwriteable, but Composer needs to write to it. This will hopefully be fixed in the future, but in the meantime, the issue can be resolved by fixing the permissions manually:

1. This command will fix it temporarily:

chmod u+w web/sites/default

2. But Drupal will harden permission again soon. To turn it off add this to settings.php:

$settings['skip_permissions_hardening'] = TRUE;

Note: 1. seems to work, 2. not

Source: https://drupal.stackexchange.com/questions/290296/composer-require-error...