title: How to override libraryDependencies in a sbt plugin?
body: <p>How would one override the <code>libraryDependencies</code> ?
  I tried: </p>
  
  <pre><code>  Keys.libraryDependencies in Compile := {
      val libraryDependencies = (Keys.libraryDependencies in Compile).value
      val allLibraries = UpdateDependencies(libraryDependencies)
      allLibraries
    }
  </code></pre>
  
  <p>So that seem to work, when I add print statement, the <code>allLibraries</code> is correct. </p>
  
  <p>However, in the next steps, it doesn't seem to have the right values:</p>
  
  <pre><code>  Keys.update in Compile := Def.taskDyn {
      val u = (Keys.update in Compile).value
  
      Def.task {
        val allModules= u.configurations.flatMap(_.allModules)
        log.info(s"Read ${allModules.size} modules:")
        u
      }
    }.value
  </code></pre>
  
  <p>The print statement only have a few modules instead of all the one I would have added in the previous step. </p>
  
  <p>Anyone have a solution ? Thanks ! </p>