Can't debug with LG Nexus 4
Couple of suggestinos that might work:


First, try to update your Android SDK with the Android SDK Manager. Sometimes, due to a old version, newer phones are not recognized.
I'm assuming you are using Windows. Wich version? x86 or x64? When you go to Device Manager and see Android Phone &gt; Android Composite ADB Interface, does it have a yellow admiration mark? If yes, the the drivers are not installed correctly.
This might be a bit trivial, but have you tryed to reboot your PC and your phone?
Also, what minSDK version do you have in your application set, and what version does your Nexus 4 have?