I have a plugin that i developed and a feature project which includes the plugin and its dependencies. I initially had the same null pointer problem when i was exporting the feature project as a deployable feature. I got past that by generating a ant build.xml. I wanted to do the same with the update site, but with no luck. I want to know why I am getting the null pointer exception upon building. Am i missing anything obvious? There is no message related to the build failure in the error log /problems view.
Eclipse will generate a p2 repository (aka an update site) when exporting from your feature.xml if you select the "Generate metadata repository option".