What is the use of org.ops4j.pax.url.mvn.defaultRepositories for the PID io.fabric8.agent

Issue

• In Fuse 6.2.1, if we create Fabric on go to Hawtio url [1], we would see

org.ops4j.pax.url.mvn.defaultRepositories= \
    file:${runtime.home}/${karaf.default.repository}@snapshots@id=karaf-default, \
    file:${runtime.data}/maven/upload@snapshots@id=fabric-upload

org.ops4j.pax.url.mvn.repositories= \
    file:${runtime.home}/${karaf.default.repository}@snapshots@id=karaf-default, \
    file:${runtime.data}/maven/upload@snapshots@id=fabric-upload, \

Removal of karaf system repo from "org.ops4j.pax.url.mvn.repositories" for the PID "io.fabric8.agent results in issues.

For example below command does not work

JBossFuse:karaf@root> cat mvn:org.fusesource/camel-sap/6.2.1.redhat-084/xml/features
Error executing command: Error resolving artifact org.fusesource:camel-sap:xml:features:6.2.1.redhat-084: Could not find artifact org.fusesource:camel-sap:xml:features:6.2.1.redhat-084 in repo_-xyz (file:///path/to/repo/jboss-fuse-intpack-1.3.0.redhat-002-maven-repository/maven-repository/)

Though the same entries are available in "org.ops4j.pax.url.mvn.defaultRepositories".

Why the Karaf System entries are not picked from "org.ops4j.pax.url.mvn.defaultRepositories"?