LeafRefContext.validateNodeData() looks like it cant process augmentation nodes,
or at least when Augmentation Node enters it, it fails on

java.lang.UnsupportedOperationException: Augmentation node has no QName
at org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier$AugmentationIdentifier.getNodeType(YangInstanceIdentifier.java:651) ~[yang-data-api-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.schema.nodes.AbstractImmutableNormalizedNode.getNodeType(AbstractImmutableNormalizedNode.java:27) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validateNodeData(LeafRefValidatation.java:251) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validateNodeData(LeafRefValidatation.java:241) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validateNodeData(LeafRefValidatation.java:270) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validateNodeData(LeafRefValidatation.java:241) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validateNode(LeafRefValidatation.java:95) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validate0(LeafRefValidatation.java:73) ~[yang-data-impl-1.1.2-Carbon.jar:na]
at org.opendaylight.yangtools.yang.data.impl.leafref.LeafRefValidatation.validate(LeafRefValidatation.java:59) ~[yang-data-impl-1.1.2-Carbon.jar:na]

From looking at the method, support for augmentations is missing, in that case it falls back to MapNode logic and fails with exception above

Appears in 1.1.2-Carbon