title: mvn dependency:tree -Dverbose hangs and never finishes
body: <p>I have a version conflict in transitive dependencies in my project, and I'm trying to use <code>mvn dependency:tree -Dverbose</code> to find the version conflict. However, whenever I run <code>mvn dependency:tree -Dverbose</code>, it just hangs and never finishes.
  I tried using the debug mode (<code>mvn --debug dependency:tree -Dverbose</code>) to find out what's going on, and it seems that it's connecting to hundreds and hundreds of repositories, that I have defined nowhere anywhere in my project, writing tracking file, using connector, using transporter, etc......  see the pastebin here for a small snippet of the things that it just does for hours and hours: <a href="https://pastebin.com/raw/L3z4u5Hj" rel="nofollow noreferrer">https://pastebin.com/raw/L3z4u5Hj</a></p>
  <p>This doesn't happen when I don't include the <code>-Dverbose</code> flag: <code>mvn dependency:tree</code> on it's own is super snappy and completes in seconds.</p>
  <p>Also, this doesn't happen for any other repositories or codebases that I have: only a specific one. But obviously I don't know what's different about this codebase than the other ones, only that the dependencies are different (assuming that some dependency is the cause of the problem.)</p>
  <p>It seems that people on the official maven mailing list ran into this issue too, but it seems they were never able to solve it either: <a href="https://www.mail-archive.com/users@maven.apache.org/msg143124.html" rel="nofollow noreferrer">https://www.mail-archive.com/users@maven.apache.org/msg143124.html</a></p>
  <p>Any help would be appreciated. If I can't figure this out, I'll have to resort to removing dependencies one by one until I find the one that is causing the problem, and that will take a very long time because this is a very large codebase.</p>
  <p>maven version:</p>
  <pre><code>Apache Maven 3.6.0
  Maven home: /usr/share/maven
  Java version: 11.0.10, vendor: Ubuntu, runtime: /usr/lib/jvm/java-11-openjdk-amd64
  Default locale: en_US, platform encoding: UTF-8
  OS name: &quot;linux&quot;, version: &quot;4.15.0-54-generic&quot;, arch: &quot;amd64&quot;, family: &quot;unix&quot;
  </code></pre>