title: How to ignore NuGet NU1605?
body: <p>I have a huge solution with many projects and in-house NuGet packages that has a pervasive dependency on Unity 4.0.1. We are evaluating migrating this solution to Unity 5.11.1 to improve performance and solve random DI-related crashes stemming from code that the Unity project outright deleted on the 5.0.0 release.</p>
  
  <p>In searching for a way to ease the migration from the outside-in two tools have been developed:</p>
  
  <ul>
  <li>A Roslyn-based source code converter</li>
  <li>A bridge that implements the Unity 5 interface but in reality maps calls transparently to a wrapped Unity 4 container interface</li>
  </ul>
  
  <p>Both tools pass their unit tests just fine and the converter managed to convert one key "leaf" project, however, we've hit a roadblock when trying to reference migrated leaf project from one inner project: The infamous <a href="https://docs.microsoft.com/en-us/nuget/reference/errors-and-warnings/nu1605" rel="nofollow noreferrer">NU1605</a>.</p>
  
  <p>I absolutely can see how the NU106 error is warranted, as the inner project still references Unity 4.0.1 and the leaf project references Unity 5.11.1. however, this is one case of the tools getting in our way: I require both versions to "co-exist", as I am manually bridging their inconsistencies.</p>
  
  <p>On paper, this should be plenty viable as the DLLs have different versions and even namespaces are different.</p>
  
  <p>Is there any way to "force" nuget into accepting this weird setup?</p>