According to this doc: http://ant.apache.org/ivy/history/latest-milestone/settings/resolvers.html#common the name attribute of the resolver is required.
Unfortunately for me for a day or so, Ivy does not error out (I'm using the ant "install" task) when that attribute is missing from one of the resolvers in my chain. Instead, it throws a NPE: problem occurred while resolving dependency: > org.springframework#spring-parent;3.1.1.RELEASE {} with null: > java.lang.NullPointerException > at java.util.Hashtable.put(Hashtable.java:432) > at java.util.Properties.setProperty(Properties.java:161) > at > org.apache.ivy.core.cache.DefaultRepositoryCacheManager.saveResolvers(DefaultRepositoryCacheManager.java:437) > at > org.apache.ivy.core.cache.DefaultRepositoryCacheManager.originalToCachedModuleDescriptor(DefaultRepositoryCacheManager.java:1075) > at > org.apache.ivy.plugins.resolver.BasicResolver.cacheModuleDescriptor(BasicResolver.java:363) > at > org.apache.ivy.plugins.resolver.BasicResolver.getDependency(BasicResolver.java:309) > at > org.apache.ivy.plugins.resolver.IBiblioResolver.getDependency(IBiblioResolver.java:503) > at > org.apache.ivy.plugins.resolver.ChainResolver.getDependency(ChainResolver.java:104) > ... Enhancement request would be for that validation to happen and a nice message be spit out instead of waiting for the NPE. Thanks for a great tool! Zac.