Sob o Debian Jessie, eu tive pela primeira vez backports no meu pacote-source.
Eu tive alguma colisão no apt, porque alguns pacotes que eu tinha instalado do link têm versões superiores nos backports.
A primeira prioridade de pino para multimídia foi 100. Eu tento definir a prioridade para backports para -1, mas não funcionou.
LANG=C cat /etc/apt/preferences
Package: *
Pin: origin deb http://http.us.debian.org/debian jessie-backports main
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=non-free
Pin-Priority: -1
Package: *
Pin: origin deb http://http.us.debian.org/debian jessie-backports main
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=main
Pin-Priority: -1
Package: *
Pin: origin deb http://http.us.debian.org/debian jessie-backports contrib
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=contrib
Pin-Priority: -1
Package: *
Pin: origin www.deb-multimedia.org
Pin-Priority: 300
'
O que há de errado com meu /etc/apt/preferences
LANG=C apt-cache policy | grep backports | egrep -i -v translat
100 http://http.us.debian.org/debian/ jessie-backports/non-free i386 Packages
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=non-free
100 http://http.us.debian.org/debian/ jessie-backports/contrib i386 Packages
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=contrib
100 http://http.us.debian.org/debian/ jessie-backports/main i386 Packages
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=main
100 http://http.us.debian.org/debian/ jessie-backports/non-free amd64 Packages
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=non-free
100 http://http.us.debian.org/debian/ jessie-backports/contrib amd64 Packages
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=contrib
100 http://http.us.debian.org/debian/ jessie-backports/main amd64 Packages
release o=Debian Backports,a=jessie-backports,n=jessie-backports,l=Debian Backports,c=main
A pasta
ls -al /etc/apt/preferences.d/
insgesamt 8
drwxr-xr-x 2 root root 4096 Jan 25 2011 .
drwxr-xr-x 6 root root 4096 Dez 11 11:53 ..
está vazio.