title: Error installing dsc21: "dsc21 : Depends: cassandra (= 2.1.8) but 2.2.0 is to be installed"
body: <p>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</p>
  
  <pre><code>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
  </code></pre>
  
  <p>this stopped working for me today and I get an error saying </p>
  
  <pre><code>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.
  </code></pre>
  
  <p>Basically I think the problem was that in the time I hadn't needed to reinstall  I think datastax pushed dsc22 and doing <code>apt-get install dsc22</code> does work. I can't upgrade right now though because it would mean upgrading all of the other software I use. </p>
  
  <p>Edit: The operating system I'm using is "ubuntu/trusty64"</p>
  
  <p>Edit2: I have tried running <code>apt-get install dsc21=2.1.8-1</code> and it produces the same error as above</p>