title: Issues with COPY when using multistage Dockerfile builds -- no such file or directory
body: <p>I'm trying to convert my project to use multi-stage builds. However, the final step always fails with an error:</p>
  
  <pre><code>Step 11/13 : COPY --from=build /bin/grafana-server /bin/grafana-server
  COPY failed: stat /var/lib/docker/overlay2/xxxx/merged/bin/grafana-server: no such file or directory
  </code></pre>
  
  <p>My Dockerfile looks like this:</p>
  
  <pre><code>FROM golang:latest AS build
  
  ENV SRC_DIR=/go/src/github.com/grafana/grafana/
  ENV GIT_SSL_NO_VERIFY=1
  
  COPY . $SRC_DIR
  WORKDIR $SRC_DIR
  
  # Building of Grafana
  RUN \
    npm run build &amp;&amp; \
    go run build.go setup &amp;&amp; \
    go run build.go build
  
  # Create final stage containing only required artifacts
  FROM scratch
  COPY --from=build /bin/grafana-server /bin/grafana-server
  
  EXPOSE 3001
  
  CMD ["./bin/grafana-server"]
  </code></pre>
  
  <p>The <code>build.go build</code> step will output artifacts to <code>./bin/</code> -- The error is pretty unhelpful other than telling me the files don't exist where I think they should exist.</p>
  
  <p>My folder structure on my machine is:</p>
  
  <pre><code>--| ~/Documents/dev/grafana/src/grafana/grafana
  --------| bin
  ------------| &lt;grafan-server builds to here&gt;
  
  --------| deploy
  ------------| docker
  ----------------| Dockerfile
  </code></pre>
  
  <p>From <code>~/Documents/dev/grafana/src/grafana/grafana</code> is where I issue: <code>docker build -t grafana -f deploy/docker/Dockerfile .</code></p>