touch: /dev/.initramfs/lupin-waited-for-devs: No such file or directory
/scripts/casper-premount/20iso_scan: line 46: can't open /dev/sr0: No medium found
Generating locales (this might take a while)...
Generation complete.
dbus-daemon[1156]: [session uid=999 pid=1156] Activating service name='org.gtk.vfs.Daemon' requested by ':1.0' (uid=999 pid=1157 comm="" label="unconfined")
dbus-daemon[1156]: [session uid=999 pid=1156] Successfully activated service 'org.gtk.vfs.Daemon'
dbus-daemon[1156]: [session uid=999 pid=1156] Activating service name='org.gtk.vfs.Metadata' requested by ':1.0' (uid=999 pid=1157 comm="" label="unconfined")
fuse: device not found, try 'modprobe fuse' first
dbus-daemon[1156]: [session uid=999 pid=1156] Successfully activated service 'org.gtk.vfs.Metadata'

(gvfsd-metadata:1168): GUdev-CRITICAL **: 07:20:20.229: g_udev_device_has_property: assertion 'G_UDEV_IS_DEVICE (device)' failed

(gvfsd-metadata:1168): GUdev-CRITICAL **: 07:20:20.229: g_udev_device_has_property: assertion 'G_UDEV_IS_DEVICE (device)' failed
A connection to the bus can't be made
Using CD-ROM mount point /cdrom/
Identifying... [2aa509fbbe31560badc5540a089d2b85-2]
Scanning disc for index files...
Found 2 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Ubuntu 18.04 LTS _Bionic Beaver_ - Release amd64 (20180426)'
This disc is called: 
'Ubuntu 18.04 LTS _Bionic Beaver_ - Release amd64 (20180426)'
Copying package lists...gpgv: Signature made Thu Apr 26 18:43:31 2018 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 18.04 LTS _Bionic Beaver_ - Release amd64 (20180426)]/ bionic main restricted
Repeat this process for the rest of the CDs in your set.