module a {
  yang-version 1.1;
  namespace "a";
  prefix a;

  container a-cont {
    leaf a-leaf-cont {
      type string;
    }
    container a-cont2 {
      leaf a-leaf-cont2 {
        type string;
      }
    }
  }
}


module b {
  yang-version 1.1;
  namespace "b";
  prefix b;
  import a {
    prefix a;
  }

  augment "/a:a-cont/a:a-cont2" {
    description
      "An augmentation of a leafref typed leaf with path to outside
       of the augmented scope and back to the module a";
    container b-cont {
      leaf b-aug-leaf {
        type leafref {
          path "../../../a-leaf-cont";
        }
      }
    }
  }
}

 
[ERROR] yang-to-sources: Unable to generate sources with org.opendaylight.mdsal.binding.maven.api.gen.plugin.CodeGeneratorImpl generator
 java.lang.IllegalArgumentException: Failed to find leafref target: ../../../a-leaf-cont in module a (QNameModule{ns=b})
 at com.google.common.base.Preconditions.checkArgument (Preconditions.java:459)
 at org.opendaylight.mdsal.binding.yang.types.AbstractTypeProvider.provideTypeForLeafref (AbstractTypeProvider.java:550)
 at org.opendaylight.mdsal.binding.yang.types.AbstractTypeProvider.javaTypeForLeafrefOrIdentityRef (AbstractTypeProvider.java:299)
 at org.opendaylight.mdsal.binding.yang.types.AbstractTypeProvider.javaTypeForSchemaDefinitionType (AbstractTypeProvider.java:193)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.resolveLeafSchemaNodeAsMethod (AbstractTypeGenerator.java:1350)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.addSchemaNodeToBuilderAsMethod (AbstractTypeGenerator.java:1051)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.resolveDataSchemaNodes (AbstractTypeGenerator.java:1004)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.containerToGenType (AbstractTypeGenerator.java:302)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.addSchemaNodeToBuilderAsMethod (AbstractTypeGenerator.java:1055)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.augSchemaNodeToMethods (AbstractTypeGenerator.java:1032)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.addRawAugmentGenTypeDefinition (AbstractTypeGenerator.java:936)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.addRawAugmentGenTypeDefinition (AbstractTypeGenerator.java:950)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.augmentationToGenTypes (AbstractTypeGenerator.java:801)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.allAugmentsToGenTypes (AbstractTypeGenerator.java:375)
 at java.util.ArrayList.forEach (ArrayList.java:1257)
 at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.<init> (AbstractTypeGenerator.java:203)
 at org.opendaylight.mdsal.binding.generator.impl.CodegenTypeGenerator.<init> (CodegenTypeGenerator.java:32)
 at org.opendaylight.mdsal.binding.generator.impl.BindingGeneratorImpl.generateTypes (BindingGeneratorImpl.java:64)
 at org.opendaylight.mdsal.binding.maven.api.gen.plugin.CodeGeneratorImpl.generateSources (CodeGeneratorImpl.java:70)
 at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesProcessor.generateSourcesWithOneGenerator (YangToSourcesProcessor.java:383)
 at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesProcessor.generateSources (YangToSourcesProcessor.java:332)
 at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesProcessor.conditionalExecute (YangToSourcesProcessor.java:159)
 at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesMojo.execute (YangToSourcesMojo.java:127)
 at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)