I need to test some signing/notarization issues with Gatekeeper and I need a completely “new” and “fresh” system for that so that I can test the app like a completely new user.
Is there an easier way for that than virtualizing a Mac on a Mac? I tried just creating a new user on my local machine, but it turns out the users share the certificates - means I can not test the issue this way since the app launches without issues because of the certificates and previous launching of the app.
No, that would be the easiest way. Some Gatekeeper dependencies such as for example certificates, trusts, invalidations, etc. are kept globally.
As you mention, just creating a new user account is not enough to get a factory-default environment - instead you would have to stop/start daemons and replace various files. It would be a lot of trouble.
If you're running on an older Mac and your tets are relatively long running, it might be easier to simply dual-boot macOS to get a fresh environment (i.e. run another installation of macOS from an external USB drive for example). It would require you to write over that external drive every time you need to start from scratch, so starting over is a more length process in comparison to simply reverting a virtual machine to a previously saved snapshot with a factory-default environment.
