I recently upgraded to 10.7.3, and when I try to debug my iOS project in the simulator for the first time after logging in, I\'m prompted with the following two alerts:
no need code. no need reinstall xcode. Do these steps:
1.close xcode.
2.open Keychain access.
3.double click your Keychain(the key icon which create from keychain.p12)
4.go to access control panel(name maybe not right)
5.enable all app access this.
6.save.
7.run your xcode project.
8.it works well.
There's a much simpler solution for this. Try running the following command:
sudo /usr/sbin/DevToolsSecurity --enable
Reinstalling Xcode 4.2.1 after upgrading to 10.7.3 seems to have fixed it for me.