[tycho-user] how to consume update site zip?

[Max Spring <m2spring@xxxxxxxxxxxxx>]

I'm trying to consume a zipped-up update site sitting in a Maven repository [1].
Tycho (0.16.0) doesn't like the naive way ("..." indicates omission):

  <repository>
    <id>activiti</id>
    <layout>p2</layout>
    <url>https://...updatesite-5.11.1.zip</url>
  </repository>

It complains

  No repository found at https://...updatesite-5.11.1.zip

Or course, I could use the maven-dependency-plugin to unpack the zip and use a file:// URL.
That works, but I doesn't work in one aggregator.
(I brought this up last Aug [2].)

Is there any alternative?

Any suggestion would be highly appreciated.

-Max

[1] https://maven.alfresco.com/nexus/content/groups/public/org/activiti/designer/org.activiti.designer.updatesite/5.11.1/org.activiti.designer.updatesite-5.11.1.zip
[2] http://dev.eclipse.org/mhonarc/lists/tycho-user/msg03177.html