Trying to use build output of other tasks fails a clean build

[rmelick]

I am attempting to add some of the built artifacts to my docker image, by using the files option when configuring docker. The modZip task is the task that builds the zip into the build/libs folder.

docker {
 ...
  dockerfile 'docker/Dockerfile'
  dependsOn modZip
  files 'docker/', 'build/libs/', 'conf.json'
}

However, when I attempt to build the project for the first time, I get the following error

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 
> file 'build/libs/' does not exist.

* Try:
Run with --stacktrace option to get the stack trace. Run with --debug option to get more log output.

BUILD FAILED

Total time: 2.089 secs

The full stacktrace looks like

* What went wrong:
A problem occurred configuring root project 
> file 'build/libs/' does not exist.

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

* Exception is:
org.gradle.api.ProjectConfigurationException: A problem occurred configuring root project .
    at org.gradle.configuration.project.LifecycleProjectEvaluator.addConfigurationFailure(LifecycleProjectEvaluator.java:79)
    at org.gradle.configuration.project.LifecycleProjectEvaluator.notifyAfterEvaluate(LifecycleProjectEvaluator.java:74)
    at org.gradle.configuration.project.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:61)
    at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:532)
    at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:93)
    at org.gradle.execution.TaskPathProjectEvaluator.configureHierarchy(TaskPathProjectEvaluator.java:42)
    at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:35)
    at org.gradle.initialization.DefaultGradleLauncher$2.run(DefaultGradleLauncher.java:125)
    at org.gradle.internal.Factories$1.create(Factories.java:22)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:52)
    at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:122)
    at org.gradle.initialization.DefaultGradleLauncher.access$200(DefaultGradleLauncher.java:32)
    at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:99)
    at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:93)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:62)
    at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:93)
    at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:82)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:94)
    at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:28)
    at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:43)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:28)
    at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:75)
    at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:45)
    at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:52)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:37)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:26)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:34)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:74)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:72)
    at org.gradle.util.Swapper.swap(Swapper.java:38)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:72)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.health.DaemonHealthTracker.execute(DaemonHealthTracker.java:47)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:66)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:72)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.health.HintGCAfterBuild.execute(HintGCAfterBuild.java:41)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50)
    at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:246)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
    at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
Caused by: java.lang.IllegalArgumentException: file 'build/libs/' does not exist.
    at com.google.common.base.Preconditions.checkArgument(Preconditions.java:145)
    at com.palantir.gradle.docker.DockerExtension.resolvePathsAndValidate(DockerExtension.groovy:115)
    at com.palantir.gradle.docker.DockerExtension$resolvePathsAndValidate.call(Unknown Source)
    at com.palantir.gradle.docker.PalantirDockerPlugin$_apply_closure6.doCall(PalantirDockerPlugin.groovy:73)
    at org.gradle.listener.ClosureBackedMethodInvocationDispatch.dispatch(ClosureBackedMethodInvocationDispatch.java:40)
    at org.gradle.listener.ClosureBackedMethodInvocationDispatch.dispatch(ClosureBackedMethodInvocationDispatch.java:25)
    at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:44)
    at org.gradle.internal.event.BroadcastDispatch.dispatch(BroadcastDispatch.java:79)
    at org.gradle.internal.event.BroadcastDispatch.dispatch(BroadcastDispatch.java:30)
    at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
    at com.sun.proxy.$Proxy10.afterEvaluate(Unknown Source)
    at org.gradle.configuration.project.LifecycleProjectEvaluator.notifyAfterEvaluate(LifecycleProjectEvaluator.java:67)
    ... 52 more

Is there a better way to reference files from other build steps?

[markelliot]

dependsOn will copy task outputs

[rmelick]

Thanks! That worked very well. I simply removed 'build/libs/' from the files list.