我想在离线环境中运行Tycho。因此，我镜像demo repository on GitHub并在具有Internet访问权限的计算机上执行命令mvn clean install。构建成功，但是当我尝试运行mvn -o install以在脱机模式下安装所有依赖项时，我收到以下异常：
C:\Users\user\Documents\MVN_Test\itp01>mvn clean -e -o install
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[WARNING] No explicit target runtime environment configuration. Build is platform dependent.
[INFO] Computing target platform for MavenProject: tycho.demo.itp01:tycho.demo.itp01:1.0.0-SNAPSHOT @ C:\Users\user\Documents\MVN_Test\itp01\tycho.demo.itp01\pom.xml
[INFO] Adding repository http://download.eclipse.org/releases/helios
[ERROR] Internal error: java.lang.RuntimeException: Failed to load p2 repository with ID 'helios' from location http://download.eclipse.org/releases/helios: Repository system is offline and no local cache available for http://download.eclipse.org/releases/helios -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.RuntimeException: Failed to load p2 repository with ID 'helios' from location http://download.eclipse.org/releases/helios
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:121)
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:497)
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)
Caused by: java.lang.RuntimeException: Failed to load p2 repository with ID 'helios' from location http://download.eclipse.org/releases/helios
at org.eclipse.tycho.p2.target.TargetPlatformFactoryImpl.loadMetadataRepository(TargetPlatformFactoryImpl.java:302)
at org.eclipse.tycho.p2.target.TargetPlatformFactoryImpl.gatherExternalInstallableUnits(TargetPlatformFactoryImpl.java:270)
at org.eclipse.tycho.p2.target.TargetPlatformFactoryImpl.createTargetPlatform(TargetPlatformFactoryImpl.java:176)
at org.eclipse.tycho.p2.target.TargetPlatformFactoryImpl.createTargetPlatform(TargetPlatformFactoryImpl.java:128)
at org.eclipse.tycho.p2.target.TargetPlatformFactoryImpl.createTargetPlatform(TargetPlatformFactoryImpl.java:1)
at org.eclipse.tycho.p2.manager.ReactorRepositoryManagerImpl.computePreliminaryTargetPlatform(ReactorRepositoryManagerImpl.java:84)
at org.eclipse.tycho.p2.resolver.P2DependencyResolver.computePreliminaryTargetPlatform(P2DependencyResolver.java:223)
at org.eclipse.tycho.core.resolver.DefaultTychoResolver.resolveProject(DefaultTychoResolver.java:109)
at org.eclipse.tycho.core.maven.TychoMavenLifecycleParticipant.afterProjectsRead(TychoMavenLifecycleParticipant.java:95)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:266)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
... 11 more
Caused by: org.eclipse.equinox.p2.core.ProvisionException: Repository system is offline and no local cache available for http://download.eclipse.org/releases/helios
at org.eclipse.tycho.p2.remote.RemoteRepositoryCacheManager.createCache(RemoteRepositoryCacheManager.java:57)
at org.eclipse.equinox.internal.p2.metadata.repository.SimpleMetadataRepositoryFactory.getLocalFile(SimpleMetadataRepositoryFactory.java:66)
at org.eclipse.equinox.internal.p2.metadata.repository.SimpleMetadataRepositoryFactory.load(SimpleMetadataRepositoryFactory.java:88)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.factoryLoad(MetadataRepositoryManager.java:57)
at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:768)
at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:668)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:96)
at org.eclipse.tycho.p2.remote.RemoteMetadataRepositoryManager.loadRepository(RemoteMetadataRepositoryManager.java:61)
at org.eclipse.tycho.p2.remote.RemoteMetadataRepositoryManager.loadRepository(RemoteMetadataRepositoryManager.java:53)
at org.eclipse.tycho.p2.target.TargetPlatformFactoryImpl.loadMetadataRepository(TargetPlatformFactoryImpl.java:298)
... 22 more
[ERROR]
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/InternalErrorException
我找到了以下信息，这些信息可能是bug：
演示离线构建失败的演示项目
问题可以通过以下步骤重现：
- rm -rf~ / .m2 / repository
- unzip demo-project.zip
- cd mvn-demo-parent / releng
- mvn clean install
- 构建成功
- mvn clean -o clean install
- 构建失败，因为“存储库系统处于脱机状态且没有可用于http：// download.eclipse.org/releases/mars的本地缓存”