warning on incorrect YAML source not clear enough

By accident, I defined a property on a node /a/b/c/d by specifying in YAML:

definition:
  config:
    /hippo:configuration/hippo:modules:
      /autoexport/hippo:moduleconfig:
        autoexport:modules:
          operation: add
          type: string
          value: [bla]

Specifying multiple path segments at an indented level (like /autoexport/hippo:moduleconfig in above example) is invalid. This produced the hard-to-relate message

WARN localhost-startStop-1 [ConfigurationTreeBuilder.addValues:687] Property '/hippo:configuration/hippo:modules/autoexport/hippo:moduleconfig/autoexport:modules' defined in 'hippo-cms-test/hap/hap-shared-addon-channel-manager [config: main.yaml]' claims to ADD values, but property doesn't exist yet. Applying default behaviour.

followed by

ERROR localhost-startStop-1 [RepositoryServlet.init:233] Error while setting up JCR repository:
[INFO] [talledLocalContainer] javax.jcr.RepositoryException: unchecked exception: java.lang.IllegalStateException: Node '/hippo:configuration/hippo:modules/autoexport/hippo:moduleconfig' defined at 'hippo-cms-test/hap/hap-shared-addon-channel-manager [config: main.yaml]' is missing the required jcr:primaryType property.

It took me quite some time to discover the problem. We should be able to produce a more helpful message, based on detecting the '/' infix in "node name" /autoexport/hippo:moduleconfig.