Default method in interface?

[dchambers]

Our build fails now that I've started making use of retrolambda (via the gradle plug-in), for a project that was a pure Java 7 code base, with one class (NodeCommander) converted to make use of Lambdas. The bit that sticks out to me as looking strange is this:

  bad class file: /home/dominicc/git-dev/brjs/brjs-core/build/classes/main/org/bladerunnerjs/model/BRJSNode.class
default method found in version 51.0 classfile

Since I'm not making any use of default methods in this, or any other interface. You can see the code for yourself here:

• Java8 support BladeRunnerJS/brjs#475

This problem happens both when I configure the JAVA_7 and JAVA_8 environment variables on my machine, and when I don't and it uses some built-in compiler. Here's the tail of the build failure log:

:brjs-core:processResources
:brjs-core:zipJsDocResources
:brjs-core:classes
:brjs-core:compileRetrolambdaMain
Retrolambda 1.1.2
Bytecode version: 51 (Java 7)
Input directory:  /home/dominicc/git-dev/brjs/brjs-core/build/retrolambda/main
Output directory: /home/dominicc/git-dev/brjs/brjs-core/build/classes/main
Classpath:        /home/dominicc/git-dev/brjs/brjs-core/build/retrolambda/main:/home/dominicc/git-dev/brjs/brjs-core/build/resources/main:/home/dominicc/git-dev/brjs/brjs-logger/build/libs/brjs-logger-v0.5-114-gabb72a7-DEV.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/commons-io/commons-io/2.3/cd8d6ffc833cc63c30d712a180f4663d8f55799b/commons-io-2.3.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.apache.commons/commons-lang3/3.1/905075e6c80f206bbe6cf1e809d2caa69f420c76/commons-lang3-3.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.slf4j/slf4j-api/1.6.6/ce53b0a0e2cfbb27e8a59d38f79a18a5c6a8d2b0/slf4j-api-1.6.6.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.google.code.gson/gson/2.2.2/1f96456ca233dec780aa224bff076d8e8bca3908/gson-2.2.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.googlecode.json-simple/json-simple/1.1.1/c9ad4a0850ab676c5c64461a05ca524cdfff59f1/json-simple-1.1.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.esotericsoftware.yamlbeans/yamlbeans/1.06/52bbb25465e93308038a6a7401899a06407b98cd/yamlbeans-1.06.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/javax.validation/validation-api/1.1.0.Final/8613ae82954779d518631e05daa73a6a954817d5/validation-api-1.1.0.Final.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.apache.bval/bval-jsr303/0.5/a23543b20bc2a3f932b4c80c94486e7e47e81324/bval-jsr303-0.5.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.martiansoftware/jsap/2.1/d17c260c8f5eb6e7d6bd75449a57edfeb53d2305/jsap-2.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.eclipse.jetty.aggregate/jetty-all-server/7.6.4.v20120524/de1e981352b2376dda62cf8f1ee1e45c89bb0871/jetty-all-server-7.6.4.v20120524.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/javax.transaction/jta/1.1/2ca09f0b36ca7d71b762e14ea2ff09d5eac57558/jta-1.1.jar:/h                                                                       ome/dominicc/.gradle/caches/modules-2/files-2.1/com.google.javascript/closure-compiler/r2180/273b22e366ab352eeda308146d77e7da700d8701/closure-compiler-r2180.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.jamesmurty.utils/java-xmlbuilder/0.6/db049c92218c35edba0f395e38eff723b1303c02/java-xmlbuilder-0.6.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/xalan/xalan/2.7.1/75f1d83ce27bab5f29fff034fc74aa9f7266f22a/xalan-2.7.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.sun.xml.stream/sjsxp/1.0.2/348fff97c4354fd58110dd1e81ebcd48146d1da9/sjsxp-1.0.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/dom4j/dom4j/1.6.1/5d3ccc056b6f056dbf0dddfdf43894b9065a8f94/dom4j-1.6.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.ostermiller/utils/1.07.00/a8828217b2dd0507fbe9e9d0b2981acfb908b590/utils-1.07.00.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/net.htmlparser.jericho/jericho-html/3.2/b8385d9836562d75df8445db00c7e9c50459af9f/jericho-html-3.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.codehaus.woodstox/woodstox-core-asl/4.2.0/7a3784c65cfa5c0553f31d000b43346feb1f4ee3/woodstox-core-asl-4.2.0.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.codehaus.woodstox/stax2-api/3.1.1/466eab062e9d1a3ce2c4631b6d09b5e5c0cbd1b/stax2-api-3.1.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/net.java.dev.msv/msv-core/2013.2.2/5af8712dbc3b5b6dc0cc8b20da4224478fc7793/msv-core-2013.2.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.thaiopensource/trang/20091111/f66f18561a4a821910b5bd7e3af58ee187af5a00/trang-20091111.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.google.code.findbugs/jsr305/1.3.9/40719ea6961c0cb6afaeb6a921eaa1f6afd4cfdf/jsr305-1.3.9.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/junit/junit/4.10/e4f1766ce7404a08f45d859fb9c226fc9e41a861/junit-4.10.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.apache.bval/bval-core/0.5/db676f443722a1412ca61b55d4b3b9c2ac96d548/bval-core-0.5.jar:/home/dominicc/.gradle/caches/modules-2/                                                                files-2.1/org.eclipse.jetty.orbit/javax.servlet/2.5.0.v201103041518/9c16011c06bc6fe5e9dba080fcb40ddb4b75dc85/javax.servlet-2.5.0.v201103041518.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.eclipse.jetty.orbit/javax.security.auth.message/1.0.0.v201108011116/864ac89e01622b020fa2104bfda379692146b3b6/javax.security.auth.message-1.0.0.v201108011116.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.eclipse.jetty.orbit/javax.mail.glassfish/1.4.1.v201005082020/b707c39fc080529c4a9ffc1df4eac58421133aaf/javax.mail.glassfish-1.4.1.v201005082020.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.eclipse.jetty.orbit/javax.activation/1.1.0.v201105071233/b394a9fbf664ca835452b3ced452710bcf79fd81/javax.activation-1.1.0.v201105071233.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.eclipse.jetty.orbit/javax.annotation/1.1.0.v201108011116/964b4bd5e4f40d6497fd302e2e66c4a4257138b3/javax.annotation-1.1.0.v201108011116.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/args4j/args4j/2.0.16/9f00fb12820743b9e05c686eba543d64dd43f2b1/args4j-2.0.16.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.google.protobuf/protobuf-java/2.4.1/c589509ec6fd86d5d2fda37e07c08538235d3b9/protobuf-java-2.4.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.json/json/20090211/c183aa3a2a6250293808bba12262c8920ce5a51c/json-20090211.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.apache.ant/ant/1.8.2/fc33bf7cd8c5309dd7b81228e8626515ee42efd9/ant-1.8.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.googlecode.jarjar/jarjar/1.1/88085e95e0c9cf49e29116bd467a5dccd07d40a0/jarjar-1.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/net.iharder/base64/2.3.8/7d2e2cea90cc51169fd02a35888820ab07f6d02f/base64-2.3.8.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/xalan/serializer/2.7.1/4b4b18df434451249bb65a63f2fb69e215a6a020/serializer-2.7.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/net.java.dev.msv/xsdlib/2013.2.2/78f6ac3ac8c076f10120ca5e2813f46e59290bc2/xsdlib-2013.2.2.jar:/h                                                                ome/dominicc/.gradle/caches/modules-2/files-2.1/net.java.dev.msv/msv-testharness/2013.2.2/c2bdb0fcee4b8551d336a10dd6d2c76fc87d670c/msv-testharness-2013.2.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/xml-resolver/xml-resolver/1.2/3d0f97750b3a03e0971831566067754ba4bfd68c/xml-resolver-1.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/xerces/xercesImpl/2.9.1/7bc7e49ddfe4fb5f193ed37ecc96c12292c8ceb6/xercesImpl-2.9.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/isorelax/isorelax/20030108/b21859c352bd959ea22d06b2fe8c93b2e24531b9/isorelax-20030108.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/relaxngDatatype/relaxngDatatype/20020414/de7952cecd05b65e0e4370cc93fc03035175eef5/relaxngDatatype-20020414.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/net.sf.saxon/saxon/8.7/68f963a06e2c384ab8d60aaa89ed0363928f6e84/saxon-8.7.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.hamcrest/hamcrest-core/1.1/860340562250678d1a344907ac75754e259cdb14/hamcrest-core-1.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/commons-beanutils/commons-beanutils-core/1.8.3/75812698e5e859f2cb587c622c4cdfcd61676426/commons-beanutils-core-1.8.3.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/org.apache.ant/ant-launcher/1.8.2/6a5466384e7e2086b13d3d281dadaa059b0d0923/ant-launcher-1.8.2.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/com.google.guava/guava/13.0.1/d6f22b1e60a2f1ef99e22c9f5fde270b2088365/guava-13.0.1.jar:/home/dominicc/.gradle/caches/modules-2/files-2.1/javax.xml.stream/stax-api/1.0-2/d6337b0de8b25e53e81b922352fbea9f9f57ba0b/stax-api-1.0-2.jar
Saving lambda class: org/bladerunnerjs/testing/specutility/engine/NodeCommander$$Lambda$1
Saving lambda class: org/bladerunnerjs/testing/specutility/engine/NodeCommander$$Lambda$2
Saving lambda class: org/bladerunnerjs/testing/specutility/engine/NodeCommander$$Lambda$3
Saving lambda class: org/bladerunnerjs/testing/specutility/engine/NodeCommander$$Lambda$4
:brjs-core:compileTestJava
warning: [path] bad path element "/home/dominicc/.gradle/caches/modules-2/files-2.1/xalan/xalan/2.7.1/75f1d83ce27bab5f29fff034fc74aa9f7266f22a/xercesImpl.jar": no such file or directory
warning: [path] bad path element "/home/dominicc/.gradle/caches/modules-2/files-2.1/xalan/xalan/2.7.1/75f1d83ce27bab5f29fff034fc74aa9f7266f22a/xml-apis.jar": no such file or directory
warning: [path] bad path element "/home/dominicc/.gradle/caches/modules-2/files-2.1/xalan/xalan/2.7.1/75f1d83ce27bab5f29fff034fc74aa9f7266f22a/serializer.jar": no such file or directory
warning: [path] bad path element "/home/dominicc/.gradle/caches/modules-2/files-2.1/com.thaiopensource/trang/20091111/f66f18561a4a821910b5bd7e3af58ee187af5a00/resolver.jar": no such file or directory
warning: [path] bad path element "/home/dominicc/.gradle/caches/modules-2/files-2.1/xalan/serializer/2.7.1/4b4b18df434451249bb65a63f2fb69e215a6a020/xml-apis.jar": no such file or directory
/home/dominicc/git-dev/brjs/brjs-core/src/test/java/org/bladerunnerjs/model/NodeTesterFactory.java:3: error: cannot access BRJSNode
import org.bladerunnerjs.model.BRJSNode;
                          ^
  bad class file: /home/dominicc/git-dev/brjs/brjs-core/build/classes/main/org/bladerunnerjs/model/BRJSNode.class
    default method found in version 51.0 classfile
    Please remove or make sure it appears in the correct subdirectory of the classpath.
:brjs-core:compileTestJava FAILED
:brjs-core:processTestResources
:cutlass-common:processResources
:bladerunner-common-servlets:processResources UP-TO-DATE
:bladerunner-common-servlets:processTestResources
:brjs-logger-binding:compileJava
:brjs-logger-binding:processResources UP-TO-DATE
:brjs-logger-binding:classes
:brjs-logger-binding:jar
:bundlers:processResources
:bladerunner-dev-servlets:processResources UP-TO-DATE
:bladerunner-dev-servlets:processTestResources
:bladerunner-prod-servlets:processResources UP-TO-DATE
:bladerunner-prod-servlets:processTestResources
:brjs-logger:compileTestJava UP-TO-DATE
:brjs-logger:processTestResources UP-TO-DATE
:brjs-logger:testClasses UP-TO-DATE
:brjs-logger:test UP-TO-DATE
:brjs-logger-binding:compileTestJava UP-TO-DATE
:brjs-logger-binding:processTestResources UP-TO-DATE
:brjs-logger-binding:testClasses UP-TO-DATE
:brjs-logger-binding:test UP-TO-DATE
:cutlass-tasks:processResources UP-TO-DATE
:brjs-runner:processResources UP-TO-DATE
:brjs-runner:processTestResources
:bundlers:processTestResources
:cutlass-common:processTestResources
:cutlass-tasks:processTestResources
:js-test-driver-bundler-plugin:processResources UP-TO-DATE
:js-test-driver-bundler-plugin:processTestResources
:old-bladerunner-tests:compileJava UP-TO-DATE
:old-bladerunner-tests:processResources UP-TO-DATE
:old-bladerunner-tests:classes UP-TO-DATE
:old-bladerunner-tests:processTestResources
:system-app-servlets:processResources
:system-app-servlets:processTestResources

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':brjs-core:compileTestJava'.
> Compilation failed with exit code 1; see the compiler error output for details.

* Try:
Run with --info or --debug option to get more log output.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':brjs-core:compileTestJava'.
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:69)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
    at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
    at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
    at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
    at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
    at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
    at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
    at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
    at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:289)
    at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.executeTask(AbstractTaskPlanExecutor.java:79)
    at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:63)
    at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:51)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:23)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:86)
    at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
    at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
    at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
    at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:67)
    at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
    at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
    at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:54)
    at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:166)
    at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:113)
    at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:81)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:64)
    at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:33)
    at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:24)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:35)
    at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:45)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:42)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:24)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.StartStopIfBuildAndStop.execute(StartStopIfBuildAndStop.java:33)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.ReturnResult.execute(ReturnResult.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:71)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:69)
    at org.gradle.util.Swapper.swap(Swapper.java:38)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:69)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:60)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:60)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:45)
    at org.gradle.launcher.daemon.server.DaemonStateCoordinator.runCommand(DaemonStateCoordinator.java:186)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy.doBuild(StartBuildOrRespondWithBusy.java:49)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.HandleStop.execute(HandleStop.java:36)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.DaemonHygieneAction.execute(DaemonHygieneAction.java:39)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.CatchAndForwardDaemonFailure.execute(CatchAndForwardDaemonFailure.java:32)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.DefaultDaemonCommandExecuter.executeCommand(DefaultDaemonCommandExecuter.java:51)
    at org.gradle.launcher.daemon.server.DefaultIncomingConnectionHandler$ConnectionWorker.handleCommand(DefaultIncomingConnectionHandler.java:155)
    at org.gradle.launcher.daemon.server.DefaultIncomingConnectionHandler$ConnectionWorker.receiveAndHandleCommand(DefaultIncomingConnectionHandler.java:128)
    at org.gradle.launcher.daemon.server.DefaultIncomingConnectionHandler$ConnectionWorker.run(DefaultIncomingConnectionHandler.java:116)
    at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64)
Caused by: org.gradle.api.internal.tasks.compile.CompilationFailedException: Compilation failed with exit code 1; see the compiler error output for details.
    at org.gradle.api.internal.tasks.compile.CommandLineJavaCompiler.executeCompiler(CommandLineJavaCompiler.java:68)
    at org.gradle.api.internal.tasks.compile.CommandLineJavaCompiler.execute(CommandLineJavaCompiler.java:50)
    at org.gradle.api.internal.tasks.compile.CommandLineJavaCompiler.execute(CommandLineJavaCompiler.java:34)
    at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:96)
    at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:49)
    at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:35)
    at org.gradle.api.internal.tasks.compile.DelegatingJavaCompiler.execute(DelegatingJavaCompiler.java:29)
    at org.gradle.api.internal.tasks.compile.DelegatingJavaCompiler.execute(DelegatingJavaCompiler.java:20)
    at org.gradle.api.internal.tasks.compile.IncrementalJavaCompilerSupport.execute(IncrementalJavaCompilerSupport.java:33)
    at org.gradle.api.internal.tasks.compile.IncrementalJavaCompilerSupport.execute(IncrementalJavaCompilerSupport.java:24)
    at org.gradle.api.tasks.compile.Compile.compile(Compile.java:67)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:63)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.doExecute(AnnotationProcessingTaskFactory.java:219)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:212)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:201)
    at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:533)
    at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:516)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
    ... 66 more


BUILD FAILED

Total time: 19.654 secs

Any help or pointers for further investigation would be much appreciated.

[dchambers]

I noticed earlier today when trying to switch from Java 8 to Java 7 in Eclipse that it got in a weird state, where it started moaning about default methods in anonymous Comparator implementations, and I wondered if this was related to the problem I'm having here.

So I created an empty project with just one test containing a lambda and 'retrolambda' was able to convert it to Java 7, but the moment I tried to implement Comparator, whether using lambdas or not, it caused the exact problem I've been seeing. I tried creating an abstract class called BaseComparator that provides concrete implementations for all the new default methods in the Compatator interface except compareTo() itself, thinking this would solve the problem, but it didn't. So it looks like the only way to use 'retrolambda' is to avoid implementing any interface with default methods, full stop.

This is very limiting, and in our case means we would have to write our own bubble sort implementation, so we could avoid the Comparator interface completely.

[luontola]

I found the cause (JDK 8 generates bridge methods to interfaces when overriding a method to refine its return type) and released Retrolambda 1.1.4 which includes a fix for it. Please try it to see if it helps (and whether there are still other issues).

I couldn't figure out how to make Gradle use the new Retrolambda version, so I could not test it on your project, but that's probably just because I don't know Gradle.

[dchambers]

Excellent work!

I too was also unable to get the Gradle plug-in to use the latest version of retrolambda, so have raised an issue (evant/gradle-retrolambda#20) to help improve the documentation in this area. Will let you know how this fix works out for me once I'm able to test it.

[dchambers]

It sounds like you've already seen this for yourself, but our complete build is now passing. Thanks so much for the rapid turn around on this.

[zubairahmad2]

i have an error please help me
Error:(26, 39) error: lambda expressions are not supported in -source 1.7
(use -source 8 or higher to enable lambda expressions)

[dchambers]

@zzubiplain, this doesn't sound like a retrolambda issue. It sounds like you are trying to compile code containing lambdas with JDK 7, whereas you need to compile with JDK 8. Once compiled however, you can then use retrolambda to convert the bytecode so that it can be run on JRE 7, provided that you didn't make use of any other Java 8 features apart from lambdas.