I'm having difficulties to inherit Time Machine backups on a new MacBook Pro. I've read many Q&A on the same topic, but none was a solution for my case (that's why I don't think this is a duplicate).

I have no access to my old MacBook Pro, so this is crucial for me. I have two Time Machine backups, one on an external Hard Drive and one on a Time Capsule. I cannot access either of them.

This is what I've tried thus far:

External Hard Drive

If I mount the drive, I can see the Backups.backupdb folder on it, but I can't access it. From the Terminal:

$ ls -l
total 240
drwxrwxr-x@ 6 giovanni.lovato  staff  204 Aug 30 10:49 Backups.backupdb

$ ls Backups.backupdb/
ls: : Operation not permitted

$ sudo ls Backups.backupdb/
ls: : Operation not permitted

Seems like I have no access to it, not even as root. I've found the use of the command vsdbutil might help, so I did try:

$ sudo vsdbutil -d /Volumes/TM

but still:

$ sudo ls Backups.backupdb/
ls: : Operation not permitted

I checked the extended attributes:

$ sudo xattr Backups.backupdb
com.apple.backupd.ThinEncryptedRecoverySets

and tried to remove them, but:

$ sudo xattr -d com.apple.backupd.ThinEncryptedRecoverySets Backups.backupdb
xattr: [Errno 1] Operation not permitted: 'Backups.backupdb'

To inherit the backups, I know I have to run tmutil associatedisk, but I cannot do this until I regain access to the backup folder.

Time Capsule

No luck with Time Capsule backup either. I've mounted the drive and run the command:

$ sudo tmutil inheritbackup /Volumes/Backup/L-C02LPHF5FD56.sparsebundle
Attaching disk image...
Enter password to access "L-C02LPHF5FD56.sparsebundle":
** /dev/rdisk4s2 (NO WRITE)
Can't open /dev/rdisk4s2: Operation not permitted
/Volumes/Backup/L-C02LPHF5FD56.sparsebundle: Attach failed: The operation couldn’t be completed. Exec format error (error 8)

I've checked /dev/rdisk4s2 permission and tried to set the write flag, unsuccessfully:

$ ls -l /dev/rdisk*
crw-r-----  1 root  operator    1,   0 Aug 30 10:43 /dev/rdisk0
crw-r-----  1 root  operator    1,   1 Aug 30 10:43 /dev/rdisk0s1
crw-r-----  1 root  operator    1,   2 Aug 30 10:43 /dev/rdisk0s2
crw-r-----  1 root  operator    1,   3 Aug 30 10:43 /dev/rdisk1
crw-r-----  1 root  operator    1,   4 Aug 30 10:43 /dev/rdisk1s1
crw-r-----  1 root  operator    1,   5 Aug 30 10:43 /dev/rdisk1s2
crw-r-----  1 root  operator    1,   6 Aug 30 10:43 /dev/rdisk1s3
crw-r-----  1 root  operator    1,   7 Aug 30 10:43 /dev/rdisk1s4
crw-r-----  1 root  operator    1,   8 Aug 30 10:43 /dev/rdisk2
crw-r-----  1 root  operator    1,   9 Aug 30 10:43 /dev/rdisk2s1
crw-r-----  1 root  operator    1,  11 Aug 30 10:43 /dev/rdisk2s2
crw-r-----  1 root  operator    1,  10 Aug 30 10:43 /dev/rdisk2s3
crw-r-----  1 root  operator    1,  12 Aug 30 10:44 /dev/rdisk3
cr--------  1 root  operator    1,  13 Aug 30 11:22 /dev/rdisk4
cr--------  1 root  operator    1,  14 Aug 30 11:22 /dev/rdisk4s1
cr--------  1 root  operator    1,  15 Aug 30 11:22 /dev/rdisk4s2

$ sudo chmod u+w /dev/rdisk4s2
chmod: Unable to change file mode on /dev/rdisk4s2: Operation not permitted

I'm totally stuck, can't find any solution elsewhere so I'm asking here for some advice!