Accumulo shell is expecting instance.volumes in client.conf instead of accumulo-site.xml

Starting with Accumulo 1.8.1 we are getting the exception as per below when the Accumulo shell is invoked:

[accumulo@master ~]$ /usr/local/accumulo/bin/accumulo shell -u root -p **removed**
2017-05-18 14:31:23,667 [zookeeper.ZooUtil] ERROR: unable obtain instance id at hdfs://master:9000/accumulo/instance_id
2017-05-18 14:31:23,669 [start.Main] ERROR: Thread 'shell' died.
java.lang.RuntimeException: Accumulo not initialized, there is no instance id at hdfs://master:9000/accumulo/instance_id
at org.apache.accumulo.core.zookeeper.ZooUtil.getInstanceIDFromHdfs(ZooUtil.java:66)
at org.apache.accumulo.core.zookeeper.ZooUtil.getInstanceIDFromHdfs(ZooUtil.java:51)
at org.apache.accumulo.shell.Shell.getZooInstance(Shell.java:511)
at org.apache.accumulo.shell.Shell.setInstance(Shell.java:473)
at org.apache.accumulo.shell.Shell.config(Shell.java:322)
at org.apache.accumulo.shell.Shell.execute(Shell.java:589)
at org.apache.accumulo.start.Main$1.run(Main.java:120)
at java.lang.Thread.run(Thread.java:745)

The location used to look up the instance_id (hdfs://master:9000/accumulo/instance_id) does not appear to be consistent with this site configuration and I am not quite sure how it is being worked out.

The Accumulo Overview web page shows that the instance exists:
Instance ID: 4264f11a-704f-4c1f-880f-08f6154232b2
Thu May 18 14:44:03 BST 2017

The instance_id file is in Hadoop's HDFS:
[accumulo@master ~]$ /usr/local/hadoop/bin/hdfs dfs -ls /user/accumulo/accumulo/instance_id
Found 1 items
rw-rr- 3 accumulo supergroup 0 2017-05-18 14:27 /user/accumulo/accumulo/instance_id/4264f11a-704f-4c1f-880f-08f6154232b2

Again, within the same environment as selected above apart for using Accumulo 1.8.0, the shell can be invoked without issues.

Here's a snippet from accumulo-site.xml:

<property>
<name>instance.volumes</name>
<value>hdfs://master:9000/user/accumulo/accumulo</value>
<description>comma separated list of URIs for volumes. example: hdfs://localhost:9000/accumulo</description>
</property>

For historical reasons our "root volume" is not / but /user/accumulo although the above stack trace suggests that / is being used as root volume.