task cp(type: Copy) {
        from file('sd1')
        into file('dirInto')
        rename { null }
   }

    Caused by: java.lang.NullPointerException
        at org.gradle.util.CollectionUtils.join(CollectionUtils.java:547)
        at org.gradle.util.CollectionUtils.join(CollectionUtils.java:517)
        at org.gradle.api.file.RelativePath.getPathString(RelativePath.java:100)
        at org.gradle.api.internal.file.copy.FileCopyAction$FileCopyDetailsInternalAction.processFile(FileCopyAction.java:43)
        at org.gradle.api.internal.file.copy.NormalizingCopyActionDecorator$1$1.processFile(NormalizingCopyActionDecorator.java:66)
        at org.gradle.api.internal.file.copy.DuplicateHandlingCopyActionDecorator$1$1.processFile(DuplicateHandlingCopyActionDecorator.java:60)
        at org.gradle.api.internal.file.copy.CopyFileVisitorImpl.processFile(CopyFileVisitorImpl.java:60)
        at org.gradle.api.internal.file.copy.CopyFileVisitorImpl.visitFile(CopyFileVisitorImpl.java:44)
        at org.gradle.api.internal.file.AbstractFileTree$FilteredFileTreeImpl$1.visitFile(AbstractFileTree.java:150)
        at org.gradle.api.internal.file.collections.SingletonFileTree.visit(SingletonFileTree.java:44)
        at org.gradle.api.internal.file.collections.FileTreeAdapter.visit(FileTreeAdapter.java:109)
        at org.gradle.api.internal.file.AbstractFileTree$FilteredFileTreeImpl.visit(AbstractFileTree.java:141)
        at org.gradle.api.internal.file.CompositeFileTree.visit(CompositeFileTree.java:58)
        at org.gradle.api.internal.file.copy.CopySpecActionImpl.execute(CopySpecActionImpl.java:37)
        at org.gradle.api.internal.file.copy.CopySpecActionImpl.execute(CopySpecActionImpl.java:24)
        at org.gradle.api.internal.file.copy.DefaultCopySpec$DefaultCopySpecResolver.walk(DefaultCopySpec.java:570)
        at org.gradle.api.internal.file.copy.DefaultCopySpec$DefaultCopySpecResolver.walk(DefaultCopySpec.java:572)
        at org.gradle.api.internal.file.copy.DefaultCopySpec.walk(DefaultCopySpec.java:380)
        at org.gradle.api.internal.file.copy.DelegatingCopySpecInternal.walk(DelegatingCopySpecInternal.java:236)
        at org.gradle.api.internal.file.copy.CopySpecBackedCopyActionProcessingStream.process(CopySpecBackedCopyActionProcessingStream.java:36)
        at org.gradle.api.internal.file.copy.DuplicateHandlingCopyActionDecorator$1.process(DuplicateHandlingCopyActionDecorator.java:44)
        at org.gradle.api.internal.file.copy.NormalizingCopyActionDecorator$1.process(NormalizingCopyActionDecorator.java:57)
        at org.gradle.api.internal.file.copy.FileCopyAction.execute(FileCopyAction.java:35)
        at org.gradle.api.internal.file.copy.NormalizingCopyActionDecorator.execute(NormalizingCopyActionDecorator.java:53)
        at org.gradle.api.internal.file.copy.DuplicateHandlingCopyActionDecorator.execute(DuplicateHandlingCopyActionDecorator.java:42)
        at org.gradle.api.internal.file.copy.CopyActionExecuter.execute(CopyActionExecuter.java:38)
        at org.gradle.api.tasks.AbstractCopyTask.copy(AbstractCopyTask.java:94)