If you choose the "manually edited" variant, then Omorc either needs to fiind an already existing manifest file or create it. You can then change the manifest manually to add imports, exports and all other kinds of OSGi headers. Osmorc will then map the bundle dependencies to IDEA module dependencies, so you actually can import a class from bundle B in bundle A after adding its package to the Import-Package header of the manifest of bundle A.

If you use Bundlor to generate the manifest you don't have a manifest file that you are manually editing. Osmorc supports this kind of approach but currently not with Bundlor. Osmorc uses Bnd in this case to create manifest files. We also have support for Maven. Osmorc will read OSGi specific metadata from Maven and use it while generating the manifest with Bnd.

Well, would it be possible for you to use Bnd instead of Bundlor?

I am not sure if using anything but bnd with the OSGi intregration is actually supported. If you build your manifest with some third party tool, like Bundlor, the OSGi integration isnt much help is it? We could add support for unsupported ways of generating the manifest, but that would mean that BEFORE the make process runs you must invoke some external build tool to generate the manifest.mf. In that case we could add something like a fourth option to the facet settings, like "Externally Controlled Manifest". There won't be much use of it though, as all the goodies like checking if you included stuff in your manifest and fixing entries won't be available.

I am adding a fix so that Osmorc will use the manifest if it exists but will not complain if it does not exist. However for building a bundle, the manifest HAS to exist. Therefore building with a non-existing manifest will not work. The intentions should kick in once a manifest exists but will not work if the specified manifest file does not exist. I am also removing all the pop-up messages. The facet settings dialog will issue a warning if the manifest does not exist and will offer a button to create it at the specified (or default) position. This seems like the most flexible yet convenient way to me right now.