Caused by: java.lang.RuntimeException: Failed to serialize org.jenkinsci.plugins.pitmutation.PitBuildAction#reports_ for class org.jenkinsci.plugins.pitmutation.PitBuildAction
	at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:256)
	at hudson.util.RobustReflectionConverter$2.visit(RobustReflectionConverter.java:224)
	at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:138)
	at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:209)
	at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:150)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:43)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:88)
	at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeItem(AbstractCollectionConverter.java:64)
	at com.thoughtworks.xstream.converters.collections.CollectionConverter.marshal(CollectionConverter.java:74)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:84)
	at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:265)
	at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:252)
	... 27 more
Caused by: java.lang.RuntimeException: Failed to serialize org.jenkinsci.plugins.pitmutation.MutationReport#mutationsByPackage_ for class org.jenkinsci.plugins.pitmutation.MutationReport
	at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:256)
	at hudson.util.RobustReflectionConverter$2.visit(RobustReflectionConverter.java:224)
	at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:138)
	at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:209)
	at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:150)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:43)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:88)
	at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeItem(AbstractCollectionConverter.java:64)
	at com.thoughtworks.xstream.converters.collections.MapConverter.marshal(MapConverter.java:79)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:84)
	at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:265)
	at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:252)