title: Allow local project to depend on local lerna packages
body: <p>I have a lerna repo for a project under development. It has several packages that depend on each other. To make development easier, none of the packages are published and they depend on the latest version of each other.</p>
  
  <p><em>Directory tree</em></p>
  
  <pre><code>foo/
    packages/
      core/
        package.json
      errors/
        package.json
  </code></pre>
  
  <p><em>foo/packages/core/package.json</em></p>
  
  <pre><code>{
    ...
    dependencies: {
      "@foo/errors": "*"
    }
  }
  </code></pre>
  
  <p>I have another project, <code>bar</code>, that I'm using to test the lerna project. Currently I'm linking to its dependencies using a local <code>file:</code> dependency:</p>
  
  <p><em>bar/package.json</em></p>
  
  <pre><code>{
    ...
    dependencies: {
      "@foo/core": "../foo/packages/core"
    }
  }
  </code></pre>
  
  <p>This approach has given me a world of trouble.</p>
  
  <ul>
  <li>Using npm, I'm constantly hit with <a href="https://github.com/npm/npm/issues/17444" rel="noreferrer">ENOENT .DELETE errors</a>. Removing my package-lock.json and reinstalling has taken years off my life.</li>
  <li>Using yarn, I've been unable to <code>yarn install</code> in <code>bar</code>. Yarn follows the <code>file:</code> dependency to <code>@foo/core</code>, sees that it depends on <code>@foo/errors</code> and doesn't know about lerna's symlink. This causes it to fail, telling me it can't find <code>@foo/errors</code>.</li>
  </ul>
  
  <p>This has made writing actual code for this project secondary to this mess of dependency management.</p>
  
  <p>How can I make this (I feel fairly simple?) project structure work? Open to lerna/yarn/npm/pnpm/shell scripts/MS DOS at this point.</p>