How to create a local P2 respository and add it to eclipse?

Question

I have a few OSGI bundles that I would like to store in a local P2 repository. I have followed this guide:

https://docs.sonatype.org/display/TYCHO/How+to+make+existing+OSGi+bundles+consumable+by+Tycho

to use eclipsec.exe to convert the folder with bundles into a P2 repository. The resulting structure is like this:

c:\test\repo
c:\test\repo\plugins
c:\test\repo\plugins\my.bundle.jar
c:\test\repo\artifacts.jar
c:\test\repo\content.jar

Now I would like to add this repository in eclipse Helios. In the eclipse update manager I select add an press the "Local..." button where I specify the path to the repo:

Name: testRepo Location: file:/C:/test/repo/

I then uncheck "Group items by category" but it just says "There are no items available".

How do I add this local repository to eclipse?