I have taken the org.eclipse.equinox.p2.examples.rcp.prestartupdate project and adapted it for use in my RCP application. I then setup an update repository that gets updated as part of my nightly build.
When I open my application it goes through the motions like it is updating - it finds the update site, generates an uninstall and install operand for each bundle correctly and says that it finished with no errors. The problem is that the plugins never actually get installed in the plugins folder even though the profile gets updated (a subsequent run states there are no updates). Next time my build runs it correctly identifies there are updates, but the same thing happens again.
I have spent days debugging and the only thing that looks out of the ordinary (not that I fully understand what is going on) is that during the final configure phase none of the TouchpointData objects have any instructions so it doesn't look like configure is doing what it should.
I really have no clue where to look next and would like to see if anyone else has any ideas.
Update:
I finally figured out what was going on.
The problem started when I built my product without the generating the metadata repository. When building through Eclipse I didn't check the "Generate metadata repository" in the export product wizards because I didn't need a p2 repository, just the product. The problem is that without checking that button the product does not install as P2 enabled causing side effects such as not generating a profile among other things.
I tried to compensate for this by manually creating a profile in code which I have since found out is a really bad idea. My original problems were created because my profile wasn't set up correctly.
Once I started exporting the product with "Generate metadata repository" checked the update started correctly installing the new plugins.
The problem I have now is that although the plugins are being installed correctly, the executable is getting trashed and I cannot launch my application any more. I am building my update site through Hudson and the binary folder which is present when I use the Eclipse Export Product wizard is missing. I am assuming that is what is going wrong now.
Any ideas why the binaries would not be building in my headless PDE build?
Figured this out also. I had assumed that all I needed was the individual launcher plugins for the platforms I wanted to build on. Since I was trying to understand the process I was copying over plugins one by one to the build server. It turns out to include the platform specific binaries in the build you need to have the org.eclipse.equinox.executable feature from the delta pack. Once I added that to the build the binaries started showing up in the output. With the binaries the update mechanism works exactly as intended.