Error after adding project dependency

Question

I use Gradle to build multiple projects laid out like this:

ares/build.gradle
ares/settings.gradle
ares/ares-gui/build.gradle
ares/ares-persistence/build.gradle
ares/ares-entities/build.gradle
ares/ares-persistence-config/build.gradle

All projects have either java or scala gradle plugins applied.

In project ares-gui I added two project dependencies:

dependencies {
    ...
    myConfiguration project(':ares-entities')
    myConfiguration project(':ares-persistence')
    ...
}

When I run gradle eclipse, I get this error:

A problem occurred evaluating project ':ares-gui'.
> Could not resolve all dependencies for configuration ':ares-gui:runtime'.
   > Module version group:ares, module:ares-gui, version:1.0.0.SNAPSHOT, configuration:runtime declares a dependency on configuration 'default' which is not declared in the module descriptor for group:ares, module:ares-persistence, version:1.0.0.SNAPSHOT

The interesting thing is that when I leave only one dependency (to ares-entities), everything is fine.

Any idea why this happens?

EDIT: This is actually very interesting: when I changed the name of ares-persistence to ares-bpersistence (lexicographically before ares-gui), the problem went away! A bug?

EDIT2: Here's some more info about the problem:

Gradle version:

------------------------------------------------------------
Gradle 1.0-milestone-9
------------------------------------------------------------

Gradle build time: wtorek, 13 marzec 2012 16:10:09 UTC
Groovy: 1.8.6
Ant: Apache Ant(TM) version 1.8.2 compiled on December 20 2010
Ivy: 2.2.0
JVM: 1.6.0_26 (Sun Microsystems Inc. 20.1-b02)
OS: Linux 2.6.38-13-generic amd64

Stacktrace:

org.gradle.api.GradleScriptException: A problem occurred evaluating project ':ares-gui'.
    at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:54)
    at org.gradle.configuration.DefaultScriptPluginFactory$ScriptPluginImpl.apply(DefaultScriptPluginFactory.java:127)
    at org.gradle.configuration.BuildScriptProcessor.evaluate(BuildScriptProcessor.java:38)
    at org.gradle.configuration.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:43)
    at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:462)
    at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:74)
    at org.gradle.configuration.ProjectEvaluationConfigurer.execute(ProjectEvaluationConfigurer.java:23)
    at org.gradle.configuration.ProjectEvaluationConfigurer.execute(ProjectEvaluationConfigurer.java:21)
    at org.gradle.configuration.DefaultBuildConfigurer$1.execute(DefaultBuildConfigurer.java:38)
    at org.gradle.configuration.DefaultBuildConfigurer$1.execute(DefaultBuildConfigurer.java:35)
    at org.gradle.api.internal.project.AbstractProject.configure(AbstractProject.java:438)
    at org.gradle.api.internal.project.AbstractProject.allprojects(AbstractProject.java:433)
    at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:35)
    at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:139)
    at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:110)
    at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:78)
    at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:45)
    at org.gradle.launcher.daemon.protocol.Build.run(Build.java:67)
    at org.gradle.launcher.daemon.protocol.Build.run(Build.java:63)
    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:122)
    at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:45)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:24)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.ReturnResult.execute(ReturnResult.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$4.call(ForwardClientInput.java:116)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$4.call(ForwardClientInput.java:114)
    at org.gradle.util.Swapper.swap(Swapper.java:38)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:114)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    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:122)
    at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:61)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    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:122)
    at org.gradle.launcher.daemon.server.exec.HandleStop.execute(HandleStop.java:36)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.CatchAndForwardDaemonFailure.execute(CatchAndForwardDaemonFailure.java:32)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.HandleClientDisconnectBeforeSendingCommand.execute(HandleClientDisconnectBeforeSendingCommand.java:21)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.StopConnectionAfterExecution.execute(StopConnectionAfterExecution.java:27)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
    at org.gradle.launcher.daemon.server.exec.DefaultDaemonCommandExecuter.executeCommand(DefaultDaemonCommandExecuter.java:55)
    at org.gradle.launcher.daemon.server.Daemon$1$1.run(Daemon.java:123)
    at org.gradle.messaging.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:66)
Caused by: org.gradle.api.artifacts.ResolveException: Could not resolve all dependencies for configuration ':ares-gui:runtime'.
    at org.gradle.api.internal.artifacts.ivyservice.ErrorHandlingArtifactDependencyResolver.wrapException(ErrorHandlingArtifactDependencyResolver.java:47)
    at org.gradle.api.internal.artifacts.ivyservice.ErrorHandlingArtifactDependencyResolver.access$000(ErrorHandlingArtifactDependencyResolver.java:26)
    at org.gradle.api.internal.artifacts.ivyservice.ErrorHandlingArtifactDependencyResolver$BrokenResolvedConfiguration.rethrowFailure(ErrorHandlingArtifactDependencyResolver.java:127)
    at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getFiles(DefaultConfiguration.java:458)
    at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.getFiles(DefaultConfiguration.java:203)
    at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration_Decorated.getFiles(Unknown Source)
    at org.gradle.api.internal.file.AbstractFileCollection$1.getFiles(AbstractFileCollection.java:88)
    at build_12d77nfltt9q8t8qb7c0m6lmai$_run_closure4_closure7.doCall(/home/ghik/iosr/ares/ares-gui/build.gradle:45)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:141)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:90)
    at org.gradle.api.plugins.osgi.OsgiPluginConvention.osgiManifest(OsgiPluginConvention.java:65)
    at org.gradle.api.internal.BeanDynamicObject$MetaClassAdapter.invokeMethod(BeanDynamicObject.java:196)
    at org.gradle.api.internal.BeanDynamicObject.invokeMethod(BeanDynamicObject.java:102)
    at org.gradle.api.internal.plugins.DefaultConvention$ExtensionsDynamicObject.invokeMethod(DefaultConvention.java:212)
    at org.gradle.api.internal.CompositeDynamicObject.invokeMethod(CompositeDynamicObject.java:99)
    at org.gradle.api.internal.project.DefaultProject_Decorated.invokeMethod(Unknown Source)
    at org.gradle.groovy.scripts.BasicScript.methodMissing(BasicScript.groovy:73)
    at build_12d77nfltt9q8t8qb7c0m6lmai$_run_closure4.doCall(/home/ghik/iosr/ares/ares-gui/build.gradle:39)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:141)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:109)
    at org.gradle.api.internal.AbstractTask.configure(AbstractTask.java:392)
    at org.gradle.api.internal.AbstractTask.configure(AbstractTask.java:57)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:133)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:90)
    at org.gradle.api.internal.DefaultNamedDomainObjectCollection$ContainerElementsDynamicObject.invokeMethod(DefaultNamedDomainObjectCollection.java:315)
    at org.gradle.api.internal.CompositeDynamicObject.invokeMethod(CompositeDynamicObject.java:99)
    at org.gradle.api.internal.project.DefaultProject_Decorated.invokeMethod(Unknown Source)
    at org.gradle.groovy.scripts.BasicScript.methodMissing(BasicScript.groovy:73)
    at build_12d77nfltt9q8t8qb7c0m6lmai.run(/home/ghik/iosr/ares/ares-gui/build.gradle:38)
    at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:52)
    ... 52 more
Caused by: java.lang.RuntimeException: Module version group:ares, module:ares-gui, version:1.0.0.SNAPSHOT, configuration:runtime declares a dependency on configuration 'default' which is not declared in the module descriptor for group:ares, module:ares-persistence-config, version:1.0.0.SNAPSHOT
    at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DependencyGraphBuilder$DependencyEdge.calculateTargetConfigurations(DependencyGraphBuilder.java:322)
    at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DependencyGraphBuilder$DependencyEdge.attachToTargetConfigurations(DependencyGraphBuilder.java:283)
    at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DependencyGraphBuilder.traverseGraph(DependencyGraphBuilder.java:117)
    at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DependencyGraphBuilder.resolve(DependencyGraphBuilder.java:53)
    at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DefaultDependencyResolver.resolve(DefaultDependencyResolver.java:67)
    at org.gradle.api.internal.artifacts.ivyservice.CacheLockingArtifactDependencyResolver$1.create(CacheLockingArtifactDependencyResolver.java:36)
    at org.gradle.api.internal.artifacts.ivyservice.CacheLockingArtifactDependencyResolver$1.create(CacheLockingArtifactDependencyResolver.java:34)
    at org.gradle.cache.internal.DefaultCacheAccess.useCache(DefaultCacheAccess.java:126)
    at org.gradle.cache.internal.DefaultPersistentDirectoryStore.useCache(DefaultPersistentDirectoryStore.java:99)
    at org.gradle.api.internal.artifacts.ivyservice.DefaultCacheLockingManager.useCache(DefaultCacheLockingManager.java:49)
    at org.gradle.api.internal.artifacts.ivyservice.CacheLockingArtifactDependencyResolver.resolve(CacheLockingArtifactDependencyResolver.java:34)
    at org.gradle.api.internal.artifacts.ivyservice.SelfResolvingDependencyResolver.resolve(SelfResolvingDependencyResolver.java:42)
    at org.gradle.api.internal.artifacts.ivyservice.ShortcircuitEmptyConfigsArtifactDependencyResolver.resolve(ShortcircuitEmptyConfigsArtifactDependencyResolver.java:78)
    at org.gradle.api.internal.artifacts.ivyservice.ErrorHandlingArtifactDependencyResolver.resolve(ErrorHandlingArtifactDependencyResolver.java:36)
    at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.getResolvedConfiguration(DefaultConfiguration.java:236)
    at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration_Decorated.getResolvedConfiguration(Unknown Source)
    at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getFiles(DefaultConfiguration.java:456)
    ... 78 more

It also turns out that the problem disappears when I remove one line from the build script:

war {
    manifest = osgiManifest {
        ...
        // this line is causing problems
        def someLibs = classpath.files.collect{ 'WEB-INF/lib/'+it.name }
        ...
    }
}

Answer 1

classpath.files in the code above resolves a file collection at build configuration time. This should be avoided whenever possible. For one thing, it means that the file collection will get resolved for each and every build (possibly involving downloads), no matter which task on which project gets executed. In this particular case, it also causes the project dependency on :ares-persistence to get resolved, which fails because that project's build script hasn't been evaluated yet.

The solution is to make sure that the file collection only gets resolved at execution time. How this is done depends on the exact circumstances of what you are trying to achieve. Common solutions are to use lazy Gradle APIs, do the work in a callback registered with one of the many hooks that Gradle provides, or do the work in a doFirst {} block.