title: VSTS: Directory 'd:\a\1\a' is empty. Nothing will be added to build artifact 'drop'
body: <p>I am making my first build in VSTS and I have had to ask a number of questions on SO.
  I have now been able to restore nuget packages and build my project but now I have to ensure the artifacts are copied to the right place.
  My last build attempt failed for this reason: Directory 'd:\a\1\a' is empty. Nothing will be added to build artifact 'drop'.
  My build is defined as;
  <a href="https://i.stack.imgur.com/9G9fR.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9G9fR.png" alt="enter image description here"></a></p>
  
  <p>The Copy Files
  <a href="https://i.stack.imgur.com/2rpNE.png" rel="noreferrer"><img src="https://i.stack.imgur.com/2rpNE.png" alt="enter image description here"></a></p>
  
  <p>The .Net Core build;
  <a href="https://i.stack.imgur.com/TvzJT.png" rel="noreferrer"><img src="https://i.stack.imgur.com/TvzJT.png" alt="enter image description here"></a></p>
  
  <p>And the publish;
  <a href="https://i.stack.imgur.com/uioGl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/uioGl.png" alt="enter image description here"></a></p>
  
  <p>And from the build I get this error; </p>
  
  <pre><code>Directory 'd:\a\1\a' is empty. Nothing will be added to build artifact 'drop'.
  </code></pre>
  
  <p>How do I fix this?</p>