Xcode iPhone project no longer debugs on my iPhone

My Xcode iPhone project no longer debugs on my iPhone.

When I run it from Xcode, it builds, downloads to iPhone, and then shows: "GDB: Running..." for half a minute, and then Xcode shows: "Error from Debugger: The program being debugged is not being run."

..and the iPhone shows 开发者_运维百科springboard.

If I click the app's icon, the app runs ok.

You're propably building with an ad hoc provisioning profile. Make sure you're building using your team development provisioning profile and that you allow debugging in your Entitlements.plist.