apt complains with:
W: Duplicate sources.list entry http://mirrors.wikimedia.org/debian/ jessie-backports/main amd64 Packages (/var/lib/apt/lists/mirrors.wikimedia.org_debian_dists_jessie-backports_main_binary-amd64_Packages)
A grep in /etc/ yields:
/etc/apt/sources.list:deb http://mirrors.wikimedia.org/debian/ jessie-backports main /etc/apt/sources.list.d/debian-backports.list:deb http://mirrors.wikimedia.org/debian/ jessie-backports main contrib non-free /etc/apt/sources.list.d/debian-backports.list:deb-src http://mirrors.wikimedia.org/debian/ jessie-backports main contrib non-free
From /dib/puppet/ciiimage.pp we use include ::apt which does:
# enable backports for Debian systems if $::operatingsystem == 'Debian' { apt::repository { 'debian-backports': uri => 'http://mirrors.wikimedia.org/debian', dist => "${::lsbdistcodename}-backports", components => 'main non-free contrib', comment_old => true, } }
I am not sure how we end up having it as well in /etc/apt/sources.list