title: Why does sbt try to resolve/download artifacts I already have locally?
body: <p>I live behind a corporate proxy, but I can "come up for air" and connect to a non-proxied internet if I need to for a while.</p>
  
  <p>I've run update/compile cycles in sbt on my project (on the public net) and have downloaded all its dependencies into my local .ivy2 directory without problem.</p>
  
  <p>Yet when I run sbt compile it still sometimes tries to re-resolve things I already "own" locally--which will hang if I try to do this behind the proxy.  Why is sbt doing this?</p>
  
  <p>I want to be able to work on my corporate net after being sure I've captured all my needed artifacts.  Not sure if behavior is different for ivy vs maven artifacts.  Happened to notice the behavior on an ivy artifact but it may affect maven pulls as well?</p>