mount: mounting /cow on /root/cow failed: No such file or directory
passwd: password expiry information changed.
dbus-daemon[893]: [session uid=999 pid=893] Activating service name='org.gtk.vfs.Daemon' requested by ':1.0' (uid=999 pid=894 comm="" label="unconfined")
dbus-daemon[893]: [session uid=999 pid=893] Successfully activated service 'org.gtk.vfs.Daemon'
dbus-daemon[893]: [session uid=999 pid=893] Activating service name='org.gtk.vfs.Metadata' requested by ':1.0' (uid=999 pid=894 comm="" label="unconfined")
fuse: device not found, try 'modprobe fuse' first
dbus-daemon[893]: [session uid=999 pid=893] Successfully activated service 'org.gtk.vfs.Metadata'
A connection to the bus can't be made
Using CD-ROM mount point /cdrom/
Identifying... [e9b97d4ab5204a4b7329fc20e630b4e5-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Ubuntu-Studio 20.04 LTS _Focal Fossa_ - Alpha amd64 (20200319)'
This disc is called: 
'Ubuntu-Studio 20.04 LTS _Focal Fossa_ - Alpha amd64 (20200319)'
Copying package lists...gpgv: Signature made Thu Mar 19 19:11:55 2020 UTC
gpgv:                using RSA key D94AA3F0EFE21092
gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key (2012) <cdimage@ubuntu.com>"

Reading Package Indexes... 0%

Reading Package Indexes... Done
Writing new source list
Source list entries for this disc are:
deb cdrom:[Ubuntu-Studio 20.04 LTS _Focal Fossa_ - Alpha amd64 (20200319)]/ focal main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.