Hi @midiguru23! I think I understand your question.
Modules will definitely not be backwards compatible, you’re right. There could hypothetically be some hybrid format that contains both V1 and V2 binaries, but I would be surprised if that’s the plan. What’s certain is that a V2 build could never run in V1.
I would assume that (either via existing behavior or by a minor update) a V1 version of Rack won’t “see” a V2 version of a plugin and therefore won’t try (and fail) to update.
In particular, what I don’t think we’ve heard (well, at least I haven’t heard) is whether there will be a V1 version of the library that works in parallel with the V2 version. I’m 100% certain this issue has occurred to Andrew but I don’t know what the plan is. In particular, I don’t know if developers will be able to officially release V1 updates through the Library after V2 is released. It may be that any such updates need to be manually managed. As you probably know, all the update is doing is downloading a new plugin ZIP file into the Rack directory, which is then uncompressed into a subdirectory when Rack is restarted, so manual updates are very easy to do.
What I’m going to do (absent an official word on this) is subscribe to and update all V1 modules just before V2 is released, and back up the module directory. That way I can make reference to any V1 module that was released, load any V1 patch, etc.