Here is a rough example of how I did it. Hope you can use it in this form.
First get root shell using "sudo su". After that you can run the following
commands.
FLIDAS=/mnt/flidas
debootstrap flidas $FLIDAS http://es.archive.trisquel.info/trisquel/
curl http://jenkins.trisquel.info/repos/trisquel/key.asc >
$FLIDAS/root/key.asc
cat <<EOF > $FLIDAS/etc/apt/sources.list
deb http://es.archive.trisquel.info/trisquel flidas main
deb http://es.archive.trisquel.info/trisquel flidas-updates main
deb http://es.archive.trisquel.info/trisquel flidas-security main
deb http://jenkins.trisquel.info/repos/trisquel/flidas flidas main
#deb http://jenkins.trisquel.info/repos/trisquel/flidas flidas-updates main
deb http://jenkins.trisquel.info/repos/trisquel/flidas flidas-security main
EOF
After doing this you will have flidas debootstrapped, with jenkins repo key
in root dir and sources list set up.
Then you can mount some stuff for flidas to have and chroot to the system.
mount --bind /dev/ /mnt/flidas/dev/
mount -t devpts none /mnt/flidas/dev/pts/
mount -t proc none /mnt/flidas/proc/
chroot /mnt/flidas/
You can now add the key.
cat /root/key.asc | apt-key add -
After updating using "apt-get update" you can install packages.
When you want to exit, just execute "exit". After that you can un-mount the
stuff you mounted previously.
umount /mnt/flidas/dev/pts
umount /mnt/flidas/dev
umount /mnt/flidas/proc
To use the system later you don't need to repeat everything, just the mount
and chroot part.
