title: What does "manifest path is a virtual manifest, but this command requires running against an actual package" mean?
body: <p>I'm trying to build a Rust project (xray). When running <code>cargo run</code> I get the following error message</p>
  <blockquote>
  <p>error: manifest path <code>D:\xray\building\xray\Cargo.toml</code> is a virtual
  manifest, but this command requires running against an actual package
  in this workspace</p>
  </blockquote>
  <p>What exactly does this mean and how can it be solved? I'm using Cargo version 0.25.0 and Rust version 1.24.1.</p>