[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: /operations/operation/effort in module enum-leafref (QNameModule{ns=urn:donaldh:yang:leafref:bug}) [org.opendaylight.mdsal.binding.yang.types.CodegenTypeProvider@35563e4c]
	at com.google.common.base.Preconditions.checkArgument(Preconditions.java:474)
	at org.opendaylight.mdsal.binding.yang.types.AbstractTypeProvider.provideTypeForLeafref(AbstractTypeProvider.java:563)
	at org.opendaylight.mdsal.binding.yang.types.AbstractTypeProvider.javaTypeForLeafrefOrIdentityRef(AbstractTypeProvider.java:319)
	at org.opendaylight.mdsal.binding.yang.types.AbstractTypeProvider.javaTypeForSchemaDefinitionType(AbstractTypeProvider.java:213)
	at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.resolveLeafListSchemaNode(AbstractTypeGenerator.java:1514)
	at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.addSchemaNodeToBuilderAsMethod(AbstractTypeGenerator.java:1008)
	at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.resolveDataSchemaNodes(AbstractTypeGenerator.java:947)
	at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.groupingsToGenTypes(AbstractTypeGenerator.java:603)
	at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.moduleToGenTypes(AbstractTypeGenerator.java:209)
	at org.opendaylight.mdsal.binding.generator.impl.AbstractTypeGenerator.<init>(AbstractTypeGenerator.java:178)
	at org.opendaylight.mdsal.binding.generator.impl.CodegenTypeGenerator.<init>(CodegenTypeGenerator.java:30)
	at org.opendaylight.mdsal.binding.generator.impl.BindingGeneratorImpl.generateTypes(BindingGeneratorImpl.java:55)
	at org.opendaylight.mdsal.binding.maven.api.gen.plugin.CodeGeneratorImpl.generateSources(CodeGeneratorImpl.java:61)
	at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesProcessor.generateSourcesWithOneGenerator(YangToSourcesProcessor.java:379)
	at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesProcessor.generateSources(YangToSourcesProcessor.java:329)
	at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesProcessor.conditionalExecute(YangToSourcesProcessor.java:156)
	at org.opendaylight.yangtools.yang2sources.plugin.YangToSourcesMojo.execute(YangToSourcesMojo.java:123)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)