Attach Android debugger to process built with Eclipse project I don't own

I would like to debug a portion of an Android application for which I do not have the original Eclipse project that was used to build it. I have built a `.jar` file that implements an Android Activity. I use Eclipse to develop and debug it, and `javac/jar` to build the `.jar` with the appropriate classes. The `.jar` is shipped off to a client, who then builds it into their application. Now they would like me to debug something, and have provided me a .apk for their application that calls `android.os.Debug.waitForDebugger()`. I do not have their source code or project. I install and run the application, and when it hits that call, I see the process in the Eclipse DDMS tab waiting on attachment (it has the red bug icon). When I try to attach to the process in Eclipse, by clicking the "Debug the selected process" button, I get this error message: No opened project found for <their-app-package-name>. Debug session failed! Is there a way for me to attach to this process, without the original application project? If not, I will resort to `android.util.Log` statements, but I would rather not, for obvious reasons. As I wrote above, I have my own project with all the source code used to build the `.jar` that was incorporated into this application. I have tried changing the package name in my test project manifest, but that does not appear to change anything as far as Eclipse is concerned. Thanks for any help!