Since updating to Xcode 6.1 all of my iOS devices will not be recognized by the Mac after a period of time. It used to be every couple of days, but now it is happening sever
I've been having this issue for over a month now. It's not just Xcode but also iTunes, Image Capture, and some other apps that should easily see my devices. I also often get the "trust this computer?" query, but not every time that the Mac starts rejecting my devices.
Instead of restarting the Mac, the other option is to quit Xcode, issue the following command in Terminal:
sudo launchctl stop com.apple.usbmuxd
and then restart Xcode