title: systemd/udev dependency failure when auto mounting separate partition during startup
body: <p><strong>EDIT:  This occurs when I am trying to use a separate partition with ANY mount point, not just <code>/var</code>.</strong></p>
  
  <p>I am using Buildroot to build an embedded linux system.  I am trying to use a separate partition for /var, but this occurs for ANY mount point.  My init system is systemd, udev for device management.  I've edited my fstab to:</p>
  
  <pre><code># &lt;file system&gt; &lt;mount pt&gt;     &lt;type&gt;   &lt;options&gt;                &lt;dump&gt; &lt;pass&gt;
  /dev/root       /              ext2     rw,noauto                0      1
  /dev/mmcblk0p4  /var           ext2     defaults                 0      2
  proc            /proc          proc     defaults                 0      0
  devpts          /dev/pts       devpts   defaults,gid=5,mode=620  0      0
  tmpfs           /dev/shm       tmpfs    mode=0777                0      0
  tmpfs           /tmp           tmpfs    defaults                 0      0
  sysfs           /sys           sysfs    defaults                 0      0
  tmpfs           /run           tmpfs    defaults                 0      0
  </code></pre>
  
  <p>Once the system boots, I receive a message "<strong>Expecting device dev-mmcblk0p4.device...</strong>", eventually followed by:</p>
  
  <p>"<strong>Timed out waiting for device dev-mmcblk0p4.device.</strong>"</p>
  
  <p>"<strong>Dependency failed for /var.</strong>"</p>
  
  <p>"<strong>Dependency failed for Local File Systems.</strong>"</p>
  
  <p><br>
  Same thing happens if I use <code>/var2</code>, or anything else, as the mount point instead of <code>/var</code>.  Once the boot fails, it enters emergency mode and the mount will then successfully occur.  I can then exit system maintenance and everything works as expected.  What is causing this delayed mount??  Have I missed a step?</p>
  
  <p>Screenshot of output:</p>
  
  <p><img src="https://i.stack.imgur.com/Qt7OH.png" alt="systemd startup"></p>