I have a dependency on a flatDir repository. When I install the artifact created by the build with that dependency (i.e. ‘gradle install’ with Maven plugin applied), it includes a dependency in the generated .pom with no group or version, just an artifact id and scope. This causes a NullPointerException on line 77 of MavenDependencyKey when I attempt to access the artifact via a dependency in another project. I had to manually edit the generated .pom in the .m2 repository to remove the flatDir dependency in order to work around this failure. Reproduced in Gradle 2.4 and 2.5. The hashCode is derived from the group id, and does not handle it if the group id is null, as it is for flatDir entries.
Here is the root cause stack trace for Gradle 2.5:
Caused by: java.lang.NullPointerException
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.data.MavenDependencyKey.hashCode(MavenDependencyKey.java:77)
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.PomReader.resolveDependencies(PomReader.java:351)
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.PomReader.getDependencies(PomReader.java:342)
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.GradlePomModuleDescriptorParser.doParsePom(GradlePomModuleDescriptorParser.java:136)
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.GradlePomModuleDescriptorParser.doParseDescriptor(GradlePomModuleDescriptorParser.java:70)
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.GradlePomModuleDescriptorParser.doParseDescriptor(GradlePomModuleDescriptorParser.java:46)
at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.parser.AbstractModuleDescriptorParser.parseDescriptor(AbstractModuleDescriptorParser.java:44)