When you rebuild your nixos system on an empty root partition, every file is just like it’s defined in your configuration. But from that point, you boot again, start up programs and change the system yourself.
All of that creates, deletes or changes files.
I’m looking for some way to see how the filesystem has changed since that clean slate.
This is because I want to set up impermanence, but it’s not always clear where files are that I may want to keep. An example would be /etc/machine-id from the impermanence examples, and otherwise any GUI applications that has a settings menu.
Is there such a tool around? Or is there some combination of programs (linux 
) I can use to accomplish this?