stdin: Not a typewriter
Generating locales...
  en_US.UTF-8... done
Generation complete.
pwconv: failed to change the mode of /etc/passwd- to 0600
Using CD-ROM mount point /cdrom/
Identifying... [ad7843179e097678ed44306943c0b0d7-2]
Scanning disc for index files...
Found 4 package indexes, 0 source indexes, 0 translation indexes and 1 signatures
Found label 'Ubuntu-MATE 15.04 _Vivid Vervet_ - Alpha i386 (20150317)'
This disc is called: 
'Ubuntu-MATE 15.04 _Vivid Vervet_ - Alpha i386 (20150317)'
Copying package lists...gpgv: Signature made Tue Mar 17 03:50:38 2015 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:[Ubuntu-MATE 15.04 _Vivid Vervet_ - Alpha i386 (20150317)]/ vivid main multiverse restricted universe
Repeat this process for the rest of the CDs in your set.

Welcome to Ubuntu Vivid Vervet (development branch)!