Xcode 4.6.2 seems quite buggy.
When I run a second time my any project I get SIGABRT crash within the first second. I completely removed Xcode and reinstalled, (yeah I try turn off and on again). Also I removed command line tools and simulators, but that didn’t help either.
ok, I found a solution. Please open the menu Product -> Scheme -> Edit Scheme, select Run YouAppName.app on the left, tab Info. Then choose GDB instead of LLDB in debugger field.
UPD: In new Xcode 4.6.3 this bug has been fixed. So just update your Xcode.
Found another way to fix this without moving the debugger to GDB. I usually just re-run an app by pressing ⌘-R while the app is running. Instead, kill the app from Xcode with ⌘-., wait 5 seconds and hit ⌘-R to run it. Counting the 5 seconds by saying "I love Xcode" seems to help too.
Edit: This issue is fixed in 4.6.3
I suppose it has something to do with the latest update of iTunes (11.0.4), because I ran into the same issue after installing the update.
We might have to wait until Apple fixes this problem and go on with the above solutions which seem to work for me also.
来源：https://stackoverflow.com/questions/16113036/xcode-4-6-2-app-crashes-on-every-second-run