Cumulus Support

Hello,
I have a problem with mono.
It is not possible for me to install a pre-version of mono 4.2.1.
lf I enter dev ........ Snapshots / 3.8, Snapshots / 3.10 or Snapshots / 4.0.5 in mono-xamarin.list, there is always the 4.2.1 installed.

Step 1
sudo apt-get remove mono-complete
Step 2
sudo apt-get autoremove
step 3
echo "deb http://download.mono-project.com/repo/debian wheezy / snapshots / x.x.x main" | sudo tee /etc/apt/sources.list.d/mono-xamarin.list
(x.x.x for 3.8, 3.10 or 4.0.5)
step 4
Control of entry in /etc/apt/sources.list.d/mono-xamarin.list whether the entry is correct.
step 5
sudo apt-get install mono-complete

Result is always:
pi @ bpi-iot-ros-ai: ~ / $ mono -V
Mono JIT compiler version 4.2.1 (Debian 4.2.1.102 + dfsg2-7ubuntu4)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors.
http://www.mono-project.com
TLS: __thread
SIGSEGV: normal
Notifications: epoll
Architecture: sleeves, vfp + hard
Disabled: none
Misc: soft debug
LLVM: supported, not enabled.
GC: sgen

Where is the mistake?

best regards
Volker

Have you done

sudo apt-get update

after adding the repository?

Mhhh, is possible.
I have done a lot in the last 3 days, since I have the Pi.
As Linux beginner I practice a lot - learning by doing.

What must I do to the downgrade to make this possible?

Hi all,
I am at my wit's end.
I have on a new SD card the Ubuntu Image

2016-07-21-ubuntu-mate-16:04-desktop-armhf-raspberry-pi-bpi-m3-sd-emmc.img

newly uploaded.

After booting of course there was no mono on the system.
The initial installation of mono I immediately performed with the 4.0.5.
Result:

pi @ bpi-iot-ros-ai: ~ / $ mono -V
Mono JIT compiler version 4.2.1 (Debian 4.2.1.102 + dfsg2-7ubuntu4)

Next, I try it with debian.

Volker