title: Yarn removes folder within installed dependency
body: <p>I am using <a href="https://github.com/yarnpkg/yarn" rel="nofollow noreferrer">Yarn</a> v0.19.1 to install some dependencies. I deleted my <code>node_modules</code> folder completely and did a fresh <code>yarn</code> install. </p>
  
  <p>I am trying to install the dependency <a href="https://github.com/Leaflet/Leaflet" rel="nofollow noreferrer">leaflet</a> using <code>yarn add leaflet</code>. The module installs successfully, except during the <code>Cleaning Modules...</code> phase, Yarn removes the <code>images</code> folder which would typically live within <code>leaflet/dist/images</code>. When I do a <code>npm install leaflet</code> this folder does not get removed.</p>
  
  <p>During a yarn install, the <code>images</code> folder is present until the <code>Cleaning modules</code> phase happens.</p>
  
  <p>Who/what is doing this? Is this something <code>yarn</code> does? Or is this something specified within the <code>leaflet</code> library? How could I resolve this?</p>
  
  <p>I checked the <code>package.json</code> in the leaflet library and nothing seemed out of the ordinary there. It runs a jake file, but even within that file nothing is being deleted related to images.</p>
  
  <p>Here is what the folder looks like, within my <code>node_modules</code> folder, for both package manager installs:</p>
  
  <p><strong>yarn</strong>
  <a href="https://i.stack.imgur.com/XpUIs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XpUIs.png" alt="yarn install"></a></p>
  
  <p><strong>npm</strong>
  <a href="https://i.stack.imgur.com/oqIoU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oqIoU.png" alt="npm install"></a></p>