title: No manual pdf created during build of R package
body: <p>I see that my recent package build no longer creates a manual even though I have not added "--no-manual" to the build settings. I didn't have this problem before - I have recently updated both devtools and roxygen2. </p>
  
  <p>Am I missing something?</p>
  
  <p>Here is how I set my project options:</p>
  
  <p><a href="https://i.stack.imgur.com/s0h7Q.png" rel="noreferrer"><img src="https://i.stack.imgur.com/s0h7Q.png" alt="enter image description here"></a></p>