(iphone) can't run instruments on device(not simulator) with xcode4?

I'd like to time-profile on device.

When I set it to run on simulator, it works fine. But once I change target to device,

xcode4 says

The selected run destination is not valid for this action.

What's up with this?

I can even run on device, just can't ru开发者_Python百科n instrument on it.(I guess "profile" is another term for "run instrument")

Thank you

Effectively it depends of what instrument you want to use. You just have to launch Instrument separately and to choose what kind of instrument you want to use, and then attach the instrument to a target.