title: How to add maven dependency from github?
body: <p>I'm trying to figure out how to configure my pom file to add a dependency that is published on Github but which does not appear in the central repository.  The jpen library is published here:</p>
  
  <p><a href="https://github.com/qupath/qupath/tree/master/maven/repo/net/sourceforge/jpen/jpen/2-150301" rel="nofollow noreferrer">https://github.com/qupath/qupath/tree/master/maven/repo/net/sourceforge/jpen/jpen/2-150301</a></p>
  
  <p>Below is what I've added to my POM file:</p>
  
  <pre><code>&lt;project&gt;
  
      ...
  
      &lt;repositories&gt;
          &lt;repository&gt;
              &lt;id&gt;msel.releases&lt;/id&gt;
              &lt;url&gt;https://github.com/qupath/qupath/tree/master/maven/repo/net/sourceforge/jpen/jpen/2-150301&lt;/url&gt;
              &lt;releases&gt;
                  &lt;enabled&gt;true&lt;/enabled&gt;
                  &lt;updatePolicy&gt;always&lt;/updatePolicy&gt;
              &lt;/releases&gt;
          &lt;/repository&gt;
      &lt;/repositories&gt;
  
      &lt;dependencies&gt;
  
          ...
  
          &lt;dependency&gt;
              &lt;groupId&gt;net.sourceforge.jpen&lt;/groupId&gt;
              &lt;artifactId&gt;jpen&lt;/artifactId&gt;
              &lt;version&gt;4.0.0&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>When I compile I get:</p>
  
  <pre><code>Failed to execute goal on project MacawSwing: 
  Could not resolve dependencies for project com.kitfox.macaw:MacawSwing:jar:1.0-SNAPSHOT: 
  Failed to collect dependencies for [com.kitfox.macaw:MacawCore:jar:1.0-SNAPSHOT (compile), 
  com.kitfox.docking:MacawDocking:jar:1.0-SNAPSHOT (compile), 
  net.sourceforge.jpen:jpen:jar:4.0.0 (compile), 
  javax.vecmath:vecmath:jar:1.5.2 (compile)]: 
  Failed to read artifact descriptor for com.kitfox.docking:MacawDocking:jar:1.0-SNAPSHOT: 
  Failure to find com.kitfox.macaw:Macaw:pom:1.0-SNAPSHOT in https://github.com/qupath/qupath/tree/master/maven/repo/net/sourceforge/jpen/jpen/2-150301 
  was cached in the local repository, resolution will not be reattempted until the update interval of msel.releases has elapsed or updates are forced -&gt; [Help 1]
  </code></pre>
  
  <p>Those other dependencies are either local on my machine or in central and compiled fine before I tried to add the jpen dependency.</p>
  
  <p>How can I fix this?</p>