[BUG] NPE #230
Description
mvn -e se.kth.castor:depclean-maven-plugin:2.0.6:depclean results in
Caused by: java.lang.NullPointerException
at com.google.common.base.Preconditions.checkNotNull (Preconditions.java:889)
at com.google.common.collect.ImmutableSet$Builder.add (ImmutableSet.java:517)
at java.util.stream.ReduceOps$3ReducingSink.accept (ReduceOps.java:169)
at java.util.stream.ReferencePipeline$3$1.accept (ReferencePipeline.java:197)
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining (ArrayList.java:1625)
at java.util.stream.AbstractPipeline.copyInto (AbstractPipeline.java:509)
at java.util.stream.AbstractPipeline.wrapAndCopyInto (AbstractPipeline.java:499)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential (ReduceOps.java:921)
at java.util.stream.AbstractPipeline.evaluate (AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.collect (ReferencePipeline.java:682)
at se.kth.depclean.graph.MavenDependencyGraph.getDirectDependencies (MavenDependencyGraph.java:204)
at se.kth.depclean.graph.MavenDependencyGraph.<init> (MavenDependencyGraph.java:51)
at se.kth.depclean.wrapper.MavenDependencyManager.dependencyGraph (MavenDependencyManager.java:106)
at se.kth.depclean.core.DepCleanManager.extractClassesFromDependencies (DepCleanManager.java:119)
at se.kth.depclean.core.DepCleanManager.execute (DepCleanManager.java:69)
at se.kth.depclean.DepCleanMojo.execute (DepCleanMojo.java:167)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126)
Apache Maven 3.9.4 (dfbb324ad4a7c8fb0bf182e6d91b0ae20e3d2dd9)
Maven home: C:\dev\maven
Java version: 17.0.9, vendor: Amazon.com Inc., runtime: C:\Users<user>\scoop\apps\corretto17-jdk\current
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"