title: Why is COPY in docker build not detecting updates
body: <p>I run a build on a node application and then use the artifacts to build a docker image. The COPY command that moves my source in place isn't detecting changes to the source files after a build; its just using the cache.</p>
  
  <p><code>Step 9/12 : COPY server /home/nodejs/app/server
   ---&gt; Using cache
   ---&gt; bee2f9334952</code></p>
  
  <p>Am I doing something wrong with COPY or is there a way to not cache a particular step?</p>