In xcode 4.2, sometimes when you\'re going to run your ios proj on simulator, the status windows says \"Attaching to myapp\", and just gets stuck there... until you cancel. Now,
seems like there seem to be a lot of things causing this, but one thing that worked for me was simply cleaning out the build folder by pressing Cmd+Option+Shift+K or alternately if you select the Product dropdown in the toolbar and hold the Option button you should see the "Clean Build Folder" option appear