title: What to do about Eclipse's "No repository found containing: ..." error messages?
body: <p>I'm running Eclipse's Helios EE bundle on Linux to which I added the subversive plugins, the m2e Maven integration and the Mylin connector for Trac. For the last couple of weeks I've been trying to install updates, and every time I get back a message like</p>
  
  <pre><code>No repository found containing &lt;something or other&gt;
  </code></pre>
  
  <p>The latest one was</p>
  
  <pre><code>An error occurred while collecting items to be installed
  session context was:(profile=epp.package.jee, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
  No repository found containing: osgi.bundle,org.eclipse.team.svn,0.7.9.I20110318-1700
  No repository found containing: osgi.bundle,org.eclipse.team.svn.core,0.7.9.I20110523-1700
  No repository found containing: osgi.bundle,org.eclipse.team.svn.help,0.7.9.I20110318-1700
  No repository found containing: osgi.bundle,org.eclipse.team.svn.mylyn,0.7.9.I20110318-1700
  No repository found containing: osgi.bundle,org.eclipse.team.svn.ui,0.7.9.I20110523-1700
  No repository found containing: org.eclipse.update.feature,org.eclipse.team.svn,0.7.9.I20110523-1700
  No repository found containing: org.eclipse.update.feature,org.eclipse.team.svn.mylyn,0.7.9.I20110523-1700
  No repository found containing: org.eclipse.update.feature,org.eclipse.team.svn.resource.ignore.rules.jdt,0.7.9.I20110523-1700
  </code></pre>
  
  <p>What does it all mean and how do I fix that? If Eclipse has been able to contact the repositories to check for new files, why isn't it able to download those files from those some repositories? Or does the error message mean something entirely different?</p>