Hi @dsweet,
Dependencies of dependencies are certainly supported! You’ll need to provide --dep-id specifications for every dep-id in your app (you might need to examine the dependencies section of your anvil.yaml to find out which dep ID your app uses for an app – older apps use the app ID, but newer apps use an opaque string starting with dep_).
If both your main app and MyLibrary depend on CustomComponent1, they might use different dep-ids to refer to it. That’s OK - you can specify two --dep-id entries that point to the same app using different dep IDs!