Add the following line to /etc/apt/sources.list
:
deb http://ftp.ch.debian.org/debian testing main
Or execute the following command (as superuser):
echo "deb http://ftp.ch.debian.org/debian testing main" >> /etc/apt/sources.list
And add the following lines to /etc/apt/preferences
:
Package: *
Pin: release a=stable
Pin-Priority: 990
Package: *
Pin: release a=testing
Pin-Priority: 900
Now you can update your apt cache and install vim from the debian testing repository:
apt-get update
apt-get -t testing install vim