Backports of new versions of KDE Platform, Plasma and Applcations as well as major KDE apps for Kubuntu.
 More info: https://launchpad.net/~kubuntu-ppa/+archive/ubuntu/backports
Press [ENTER] to continue or ctrl-c to cancel adding it

Traceback (most recent call last):
  File "/usr/bin/apt-add-repository", line 163, in <module>
    if not sp.add_source_from_shortcut(shortcut, options.enable_source):
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 750, in add_source_from_shortcut
    self.set_modified_sourceslist()
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 484, in set_modified_sourceslist
    self.save_sourceslist()
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 650, in save_sourceslist
    self.sourceslist.save()
  File "/usr/lib/python3/dist-packages/aptsources/sourceslist.py", line 415, in save
    files[source.file] = open(source.file, "w")
FileNotFoundError: [Errno 2] No such file or directory: '/etc/apt/sources.list.d/kubuntu-ppa-backports-trusty.list'
gpg: keyring `/tmp/tmpho5922ut/secring.gpg' created
gpg: keyring `/tmp/tmpho5922ut/pubring.gpg' created
gpg: requesting key 8AC93F7A from hkp server keyserver.ubuntu.com
gpg: /tmp/tmpho5922ut/trustdb.gpg: trustdb created
gpg: key 8AC93F7A: public key "Launchpad Kubuntu Updates" imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)
OK