Why Xcode Can't Find My Connected Device

There are many ways to fail launching an application in your device. This was a new one!

iPhone is running iOS 4.1, but project "Deployment Target" is set to 4.3. As result this project does not show your device in Scheme list. Switch to another project with a compatible deployment target and your device is on the list!

Xcode4 completely failed to help debugging this case, in all possible ways.

How to Clear Project Build Results

You have a project with several targets, of which at least one fails. You can see this at Xcode4 iTunes-styled toolbar info window at top.

Except that The Target that you just build was just fine. No warnings, no errors. Xcode4 still tells something went wrong!