title: Relative path in volume mapping of Docker compose does not work under Windows
body: <p>I am using Docker Toolbox 1803 under Windows 10 64bit.</p>
  <p>I am trying to run <a href="https://github.com/openzipkin/docker-zipkin" rel="nofollow noreferrer">docker zipkin</a> in my local system, and got failure when ran the following command in Toolbox GuickStart Terminal.</p>
  <p><code>docker-compose -f docker-compose.yml  -f docker-compose-cassandra.yml up</code></p>
  <p>The following line of docker-compose.yml caused the problem.</p>
  <pre><code>version: '2'
  
    ...
    prometheus:
  
      volumes:
        - ./prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
  </code></pre>
  <p>The failure info is like following:</p>
  <pre><code>ERROR: for 80b791289250_prometheus  Cannot start service prometheus: b'OCI runtime create failed: container_linux.go:348: starting container process caused &quot;process_linux.go:402: container init caused \\&quot;rootfs_linux.go:58: mounting \\\\\\&quot;/e/FreelanceProjects/myapp/docker-zipkin/prometheus/prometheus.yml\\\\\\&quot; to rootfs \\\\\\&quot;/mnt/sda1/var/lib/docker/aufs/mnt/277f74637f71455a7b1ab4e421cf629b926f3bcbe216c3e109e029c49502b5a1\\\\\\&quot; at \\\\\\&quot;/mnt/sda1/var/lib/docker/aufs/mnt/277f74637f71455a7b1ab4e421cf629b926f3bcbe216c3e109e029c49502b5a1/etc/prometheus/prometheus.yml\\\\\\&quot; caused \\\\\\&quot;not a directory\\\\\\&quot;\\&quot;&quot;:Starting zipkin                  ... done
   if the specified host path exists and is the expected type'
  
  ERROR: for prometheus  Cannot start service prometheus: b'OCI runtime create failed: container_linux.go:348: starting container process caused &quot;process_linux.go:402: container init caused \\&quot;rootfs_linux.go:58: mounting \\\\\\&quot;/e/FreelanceProjects/myapp/docker-zipkin/prometheus/prometheus.yml\\\\\\&quot; to rootfs \\\\\\&quot;/mnt/sda1/var/lib/docker/aufs/mnt/277f74637f71455a7b1ab4e421cf629b926f3bcbe216c3e109e029c49502b5a1\\\\\\&quot; at \\\\\\&quot;/mnt/sda1/var/lib/docker/aufs/mnt/277f74637f71455a7b1ab4e421cf629b926f3bcbe216c3e109e029c49502b5a1/etc/prometheus/prometheus.yml\\\\\\&quot; caused \\\\\\&quot;not a directory\\\\\\&quot;\\&quot;&quot;: unknown: Are you trying to mount a directory onto a file (or vice-versa)? Check if the specified host path exists and is the expected type'
  ERROR: Encountered errors while bringing up the project. 
  </code></pre>
  <p><strong>UPDATE</strong>: I have set env variable <code>COMPOSE_CONVERT_WINDOWS_PATHS=1</code>, it still does not work.</p>
  <p><strong>Update</strong>: Switched to Docker for Windows and WSL2. The experience is great enough, but sadly I have to give up my VirutalBox.</p>