Duplicate folder items in user Library folder

[SaguaroSeven]

Today I was snooping around for some Auto Unlock files in my ~/Library folder and I found a assortment of folders with duplicate (or "redundant" in GB) named folders. These folders don't appear when I view the directory via Terminal.

Can anyone explain what's going on here? (I'm on an M1 MacBook Pro with clean install of Big Sur ~6 Feb.)

 

[appltech]

It's in the Containers folder. This one is special. Apps on macOS work in "containers", meaning they cannot write to anywhere they like on the drive. So, they save some auxiliary data inside Containers. There can be anything - caches, preferences, icons, temporary data - anything. No way anyone can tell what's there and why exactly.

 

[SaguaroSeven]

Ah, thanks. Lots of strange things to unpack here. The collection of apps with duplicate folders are strange. I don't use Apple Podcasts, which gets 3 folders, while Photos gets 3 and Pixelmator Pro gets 4? Some Pixelmator folders get the app's icon, one doesn't. Very confusuing. I guess the best approach is to think about something that matters...

 

[svenmany]

I also have some duplicates in my Containers folder. Understandable if you've moved on since the Containers folder is not to be managed by users. But, just for fun, I looked a bit a noticed something which could be a clue as to why we see duplicates.

In terminal I can see a number of directories named starting with "com.apple.mail". None of these are visible in the Finder, even when showing invisible files and folders. However, there are a bunch of folders visible in the Finder named "Mail". Maybe there is some metadata about a folder that governs how the Finder displays that folder, including its name. So it could be that different folders are just displaying the same name.

To be honest, this is just a guess.

 

[SaguaroSeven]

I also have some duplicates in my Containers folder. Understandable if you've moved on since the Containers folder is not to be managed by users. But, just for fun, I looked a bit a noticed something which could be a clue as to why we see duplicates.

Ah ha. I didn't realized I'd opened the Containers folder. I guess that explains it.