Java 9 specific class files
/META-INF/versions/9/org/jboss/marshalling/reflect/JDKSpecific.class
/META-INF/versions/9/org/jboss/marshalling/reflect/JDKSpecific$1.class
in the multi-release module
$JBOSS_HOME/modules/system/layers/base/org/jboss/marshalling/main/jboss-marshalling-2.0.0.Beta8-redhat-1.jar
are missing source file in jboss-eap-7.1.0.ER1-maven-repository.zip

Actually there are only .class (instead of expected .java) files in
jboss-eap-7.1.0.ER1-maven-repository.zip/jboss-eap-7.1.0.Beta1-maven-repository/maven-repository/org/jboss/marshalling/jboss-marshalling/2.0.0.Beta8-redhat-1/jboss-marshalling-2.0.0.Beta8-redhat-1-sources.jar/META-INF/versions/9/org/jboss/marshalling/reflect/