Creating a jbosstools-directory.xml with:

<directory xmlns="http://www.eclipse.org/mylyn/discovery/directory/">
<entry url="file:///Users/max/code/jbosstools/jbosstools-central/central/plugins/org.jboss.tools.central.discovery/target/org.jboss.tools.central.discovery-1.2.0-SNAPSHOT.jar" permitCategories="true"/>
</directory>

loads, but fails to fetch the directory.xml content in this jar on central update page.

It should not be necessary to use http:// for testing this.