as stable as Stable?

Linux Mint Debian Edition 2 ("Betsy") and Debian Jessie (the current Debian Stable) differ in some important ways besides LMDE 2's quicker and easier installation and set-up. LMDE 2 is based on Jessie, but package updates are not handled the same as in Jessie.

The /etc/apt/sources.list file in LMDE 2 is essentially a blank document. The distro's official repositories are stored in /etc/apt/sources.list.d/official-package-repositories.list, which by default looks like this:

deb http://packages.linuxmint.com betsy main upstream import

deb http://ftp.us.debian.org/debian jessie main contrib non-free
deb http://ftp.us.debian.org/debian jessie-updates main contrib non-free
deb http://security.debian.org jessie/updates main contrib non-free

deb http://www.deb-multimedia.org jessie main non-free

deb http://extra.linuxmint.com betsy main


By contrast, my /etc/apt/sources.list file in Debian Jessie contains only the following lines:

deb http://ftp.us.debian.org/debian jessie main contrib non-free
deb http://ftp.us.debian.org/debian jessie-updates main contrib non-free
deb http://security.debian.org jessie/updates main contrib non-free


I have no apt-pinning set up in my Jessie installation; the /etc/apt/sources.list.d/ and /etc/apt/preferences.d/ directories are empty. LMDE 2 ships with the following files in /etc/apt/preferences.d/:

# /etc/apt/preferences.d/official-extra-repositories.pref

Package: *
Pin: origin build.linuxmint.com
Pin-Priority: 700

Package: *
Pin: release o=LP-PPA-gwendal-lebihan-dev-cinnamon-nightly
Pin-Priority: 700

Package: *
Pin: origin download.virtualbox.org
Pin-Priority: 700


# /etc/apt/preferences.d/official-package-repositories.pref

Package: *
Pin: release o=linuxmint
Pin-Priority: 700

Package: *
Pin: origin packages.linuxmint.com
Pin-Priority: 700

Package: *
Pin: release o=Debian
Pin-Priority: 500


So, there's a lot more going on in LMDE 2 than just Debian Stable. Basically, Mint packages (pin-priority 700) have priority over the same packages from Debian (pin-priority 500). Also, Mint's Update Manager (you're supposed to use that for updating instead of Synaptic) is set to allow only "safe," Linux Mint approved updates, according to Mint's "Levels" system:

This is actually a nice set-up because with all of the special Mint packages included in LMDE 2, you want to feel sure that updates won't break anything. LMDE 2 isn't "straight" Debian Jessie, but the added precautions (which, in the past, I've labeled as "excessive hand-holding") should, in theory at least, make LMDE 2 about as "stable" as Debian Stable.