Change record status: 
Project: 
Introduced in branch: 
8.7.x
Introduced in version: 
8.7.0
Description: 

A new method, getSourceStorage() has been added to \Drupal\Core\Config\ConfigInstallerInterface. The method has also been implemented on the \Drupal\Core\Config\ConfigInstaller and is necessary for module install to work during config synchronization. The default implementation is to return whatever has been set using \Drupal\Core\Config\ConfigInstallerInterface::setSourceStorage() and NULL is the setter has not been called.