Error installing dsc21: "dsc21 : Depends: cassandra (= 2.1.8) but 2.2.0 is to be installed"

Question

So I'm attempting to install dsc21 using methods that have been working for me for the past couple of months. The commands I use are below

echo "deb http://debian.datastax.com/community stable main" | tee -a /etc/apt/sources.list.d/cassandra.sources.list
curl -L http://debian.datastax.com/debian/repo_key | apt-key add -
apt-get -q -y install dsc21

this stopped working for me today and I get an error saying

Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 dsc21 : Depends: cassandra (= 2.1.8) but 2.2.0 is to be installed
E: Unable to correct problems, you have held broken packages.

Basically I think the problem was that in the time I hadn't needed to reinstall I think datastax pushed dsc22 and doing apt-get install dsc22 does work. I can't upgrade right now though because it would mean upgrading all of the other software I use.

Edit: The operating system I'm using is "ubuntu/trusty64"

Edit2: I have tried running apt-get install dsc21=2.1.8-1 and it produces the same error as above

Answer 1

Following the error, specify the correct version for the cassandra package, too! apt-get install dsc21=2.1.8-1 cassandra=2.1.8