Use case: wipe data from test installation in order to start over quickly...
1. drop/empty the db
2. delete ./files and its contents
3. delete settings.php
4. visit site to re-start the installation process
As it is now, the installer complains about a missing settings.php:

So I had to extract a fresh copy of the file in order to carry on. Can we ship a default-settings.php file and have the installer create a copy of it instead of complaining in this case?
Recent comments
Hi Ernst, there seem to be a lot of modules involved, so it's not clear which one causes the trouble. I don't think, it's core. But I also don't think it's Leaflet. I verified with...
Disappearing administration bar. Is this a Leaflet or a Backdrop bug?
Do any of these issues help to identify the problem?
Error: Class "ModuleUpdater" not found
I am having the same problem trying to update from 1.33.2 to 1.34.0 Error: Class 'CoreUpdater' not found in installer_authorize_batch_copy_project()
Error: Class "ModuleUpdater" not found