When I tried to launch an Android app in debug mode, the following error message appeared and the app wouldn’t start at all.

■ Error Message

Waiting for Debugger - Application XXX is waiting for the debugger to Attach

■ Solution

Restart Eclipse

[Reference]

・あかばね式 [Android] 「Waiting for Debugger」 メッセージが消えずにハマった

That’s all from the Gemba.