getting the same error as OP
--
package update-motd None failed to install/upgrade: subprocess
post-installation script returned error exit status 1
https://bugs.launchpad.net/bugs/270731
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
** Attachment added: DpkgTerminalLog.txt
http://launchpadlibrarian.net/17633741/DpkgTerminalLog.txt
** Changed in: update-motd (Ubuntu)
Status: New = Invalid
--
package update-motd None failed to install/upgrade: subprocess
post-installation script returned error exit status 1
