touch: /dev/.initramfs/lupin-waited-for-devs: No such file or directory
Generating locales (this might take a while)...
Generation complete.
grep: /root/preseed/ubuntu.seed: No such file or directory
pwconv: failed to change the mode of /etc/passwd- to 0600
Using CD-ROM mount point /cdrom/
Identifying... [934c7b999d06f953143c3760db5c0f92-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Lubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)'
This disc is called: 
'Lubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)'
Copying package lists...gpgv: Signature made Wed Apr 20 23:09:20 2016 UTC using DSA key ID FBB75451
gpgv: Good signature from "Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.com>"

Reading Package Indexes... 0%

Reading Package Indexes... Done
Writing new source list
Source list entries for this disc are:
deb cdrom:[Lubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.