Trying to wrap my head around this…
Even if there was a way to skip installing development dependencies that you don’t need: When you install micrate as a dependency, its postinstall hook builds it as an app and thus requires the app dependencies anyway.
So IMO the main issue here is postinstall forcing a build on you for an app that you don’t even need (c.f. Shards' `postinstall` considered harmful).
And if micrate (as a library) doesn’t have hard dependencies on all database shards, it shouldn’t declare them as such.
I’m doubting the dependency system should be bother with this complexity.
If a shard has significantly different dependencies as an app, compared to being used as a lib, it might make sense to have two shards then, with different dependencies.