Universal app: only build classic toolkit
<p>I have to create a universal app from scratch. First the classic app, and at some point in the future, the modern app. I have generated the app using Cmd.</p>

<p>I have implemented the basics I need for the classic app, split off everything that can be reused in the modern app and put it into the shared directory. The problem is that now, when I compile with Cmd, I get the error that dependencies are missing (because views are missing in the modern app that I have implemented for classic only, but are required in shared code).</p>

<p>The classic app compiles find, but modern doesn't, and if there are ever errors in the classic app build process, no one will notice, because modern throws errors.</p>

<p>Can I tell Cmd on the command line to only compile the classic toolkit?</p>