Repeating /Systems/Volumes/Data/Systems/Volumes/Data I'm using ncdu to see where my storage space is going, and noticed a seemingly endless file path it seems to be traversing:

/System/Volumes/Data/System/Volumes/Data/System/Volumes/Data/System/Volumes/Data/System/Volumes...

This file path doesn't actually exist if I try to cd in there (thank goodness):

$ ls -lshart /System/Volumes/Data/System/
total 0
0 drwxr-xr-x@  3 root  wheel    96B Aug 24  2019 .
0 drwxr-xr-x   9 root  wheel   288B Sep 29  2019 Library
0 drwxr-xr-x  26 root  wheel   832B Apr 20 02:15 ..


But it does seem that I'm inexplicably using more data than I think I am; ncdu says I'm using about 40GB under the user space, and I try to keep the machine fairly uncluttered. XCode and Docker are the largest applications of the few I have, by far.

For example, ncdu is telling me I'm using 487GB (and counting), while the machine has only an 120GB SSD:

Total items: 17767208 size: 484.7 GiB


On Catalina 1.15.4.



Related: What&#39;s /System/Volumes/Data?
This is a problem with firmlinks which are used by macOS and not supported by ncdu.
You can use ncdu --exclude /System/Volumes/Data -x / on macOS Catalina to avoid the problem and scan the whole file system.