Assuming I need to apply the same rules for both an application project and a library project on which it relies, do I need to duplicate the content of proguard.cfg from the application to the library project?
In other words, does the application's proguard.cfg "take over" all the library projects on which it depends, or must I explicitly specify rules for each of the library projects?
Library projects by themselves don't run ProGuard, so they don't use any configuration.
Application projects obfuscate the entire code base, including any referenced libraries, so they need proper configuration for the application code and for the library code.