http://forums.gradle.org/gradle/topics/-2-3-rc-1-regression-npe-in-uploadarchives

when having a dependency with a null version, a nullpointer exception occurs in the mapToMavenSyntax logic:

{{Caused by: java.lang.NullPointerException
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.strategy.DefaultVersionSelectorScheme.parseSelector(DefaultVersionSelectorScheme.java:21)
at org.gradle.api.publication.maven.internal.MavenVersionRangeMapper.map(MavenVersionRangeMapper.java:28)
at org.gradle.api.publication.maven.internal.ant.DefaultPomDependenciesConverter.mapToMavenSyntax(DefaultPomDependenciesConverter.java:135)
at org.gradle.api.publication.maven.internal.ant.DefaultPomDependenciesConverter.createMavenDependency(DefaultPomDependenciesConverter.java:125)
at org.gradle.api.publication.maven.internal.ant.DefaultPomDependenciesConverter.createMavenDependencyFromDependencyDescriptor(DefaultPomDependenciesConverter.java:113)
at org.gradle.api.publication.maven.internal.ant.DefaultPomDependenciesConverter.addFromDependencyDescriptor(DefaultPomDependenciesConverter.java:104)
at org.gradle.api.publication.maven.internal.ant.DefaultPomDependenciesConverter.convert(DefaultPomDependenciesConverter.java:47)
at org.gradle.api.publication.maven.internal.DefaultMavenPom.getGeneratedDependencies(DefaultMavenPom.java:158)
at org.gradle.api.publication.maven.internal.DefaultMavenPom.getEffectivePom(DefaultMavenPom.java:168)
at org.gradle.api.publication.maven.internal.DefaultMavenPom.writeTo(DefaultMavenPom.java:189)
at org.gradle.api.publication.maven.internal.DefaultMavenPom$1.execute(DefaultMavenPom.java:199)
at org.gradle.api.publication.maven.internal.DefaultMavenPom$1.execute(DefaultMavenPom.java:197)
at org.gradle.internal.IoActions$TextFileWriterIoAction.execute(IoActions.java:110)
... 80 more}}

In general this still leads to an invalid pom file which might or might not result in an exception when the pom file is validated. It turns out that the maven pom validation from used in the maven ant tasks we use under the hood of the uploadArchives task is flaky.