I had the same issue.
I am trying to move my files from an old Linux Mint 18.2 home to my new Ubuntu 17.10 home.
Using the Ubuntu 17.10 Live CD I could mount both my Linux Mint as well as my Ubuntu encrypted homes.
For both installation I know the password and the passphrase.
On my up to date Ubuntu 17.10 I got the error.
$ sudo ecryptfs-recover-private /media/me/a1fe04d7-8591-0ee024c5b4a8/home/.ecryptfs/sebastian/.Private/INFO: Found [/media/me/a1fe04d7-8591-0ee024c5b4a8/home/.ecryptfs/oldme/.Private/].
Try to recover this directory? [Y/n]: Y
INFO: Found your wrapped-passphrase
Do you know your LOGIN passphrase? [Y/n] Y
INFO: Enter your LOGIN passphrase...
Passphrase:
Inserted auth tok with sig [9db6---81f] into the user session keyring
mount: /tmp/ecryptfs.WRoO9ZO5: mount(2) system call failed: No such file or directory.
ERROR: Failed to mount private data at [/tmp/ecryptfs.WRoO9ZO5].
I had the same issue.
I am trying to move my files from an old Linux Mint 18.2 home to my new Ubuntu 17.10 home.
Using the Ubuntu 17.10 Live CD I could mount both my Linux Mint as well as my Ubuntu encrypted homes.
For both installation I know the password and the passphrase.
On my up to date Ubuntu 17.10 I got the error.
$ sudo ecryptfs- recover- private /media/ me/a1fe04d7- 8591-0ee024c5b4 a8/home/ .ecryptfs/ sebastian/ .Private/ INFO: Found [/media/ me/a1fe04d7- 8591-0ee024c5b4 a8/home/ .ecryptfs/ oldme/. Private/ ]. WRoO9ZO5: mount(2) system call failed: No such file or directory. WRoO9ZO5] .
Try to recover this directory? [Y/n]: Y
INFO: Found your wrapped-passphrase
Do you know your LOGIN passphrase? [Y/n] Y
INFO: Enter your LOGIN passphrase...
Passphrase:
Inserted auth tok with sig [9db6---81f] into the user session keyring
mount: /tmp/ecryptfs.
ERROR: Failed to mount private data at [/tmp/ecryptfs.