title: Nuget pack only including dependencies for some projects
body: <p>I have a solution with two projects.</p>
  
  <pre><code>/Root/
        xxx.sln          
       /P1         
       /P2
  </code></pre>
  
  <p>I have defined a nuspec for both projects. P2 reference p1.</p>
  
  <p>I have following build events for both projects:
  del $(ProjectDir)*.nupkg
  nuget pack $(ProjectPath) -IncludeReferencedProjects -OutputDirectory $(ProjectDir) -Prop Configuration=Release</p>
  
  <p>P2 package do include dependencies to external nugets and p1.
  p1 contains no dependencies, even though I have added many nuget packages to it.</p>
  
  <p>What reasons can there be for not having any dependencies in the package?</p>