Choosing which new repository to add

Hiya,

first things first, here’s the template from the sticky:

Device: Raspberry Pi 2 Model B
Installation media: SDcard
Connection: Wired
Power Supply Type: Official PSU
Power specs:
Peripherals: Microsoft Xbox 360 Wireless Controller, HDD via USB-SATA adaptor with its own PSU
Storage Device: SDcard, HDD
OSMC version: 2015.07-1
XBMC version: 11:12:36 61322.921875 T:1956339712 NOTICE: Starting Kodi (15.1-RC1 Git:Unknown). Platform: Linux ARM (Thumb) 32-bit
11:12:36 61322.921875 T:1956339712 NOTICE: Using Release Kodi x32 build (version for Raspberry Pi)
Codecs: mpeg2
Audio/Video Output: composite video and analogue audio via 3,5 mm jack
Overclocked: no
Config.txt Extras: none
LINK to uploaded logs in pastebin (must include COMPLETE Kodi debug log): -

Apart from it being a media center, I’d like to use the Pi2 with OSMC as an XMPP/Jabber server running Prosody, just as I did with RaspBMC and the Pi1. As the Prosody versions from the RaspBMC repos were always quite old, I thought about using the latest ones directly from the Prosody project as described here. So I edited the /etc/apt/sources.list, added the line

deb http://packages.prosody.im/debian jessie main

and imported the key, then ran sudo apt-get update. This gave (manually translated to English)

Error retrieving http://packages.prosody.im/debian/dists/jessie/InRelease  Expected Entry »main/binary-armhf/Packages« could not be found in release file (wrong entry in sources.list or malformed file).

I know the error lies in the wrong version/repos/architecture, but I honestly cannot figure out which one to use. I know OSMC is based on Debian Jessie, that Debian is available in stable, testing and unstable and for different architectures (x86, ARM, MIPS etc.). How do I determine which repo to use? The recommended command lsb_release -sc isn’t even available. Even as a desktop user of Kubuntu for 3 years, I have to admit I’m confused.

Maybe it’s impossible to use the latest Prosody project repos because they’re only made for x86 and the Pi2 is ARM. I don’t know. If I’m not mistaken, there’s still the possibility to compile it from scratch on the Pi2, but I’d like to stay away from that.

Any explanation is deeply appreciated. Thanks in advance!