Xcode 4.3.1 cannot attach to iOS Simulator (SOLVED)

So I downloaded Xcode 4.3.1 with the latest iOS SDK from the App Store and I’m not impressed at all. While Xcode 4.3.1 can run my old iOS apps in iOS Simulator without a problem, any new project created with this version of Xcode cannot be attached as a debug process to iOS Simulator at all. What does that mean? It means I have to wait endlessly for my apps to run on the simulator and at the end, they simply don’t run. I will end up with a black screen and the Xcode’s top bar keeps saying “Attaching to …” the app name…

Have you come across this problem?

Update 1 (Solution):

I managed to find the issue. The problem is with LLDB. LLDB is the default debugger which Xcode 4.3.1 chooses for every new iOS app. Once I changed my debugger from LLDB to GDB, I can run and debug my iOS apps on iOS Simulator. I hope this will be of help to those facing the same issue.

19 thoughts on “Xcode 4.3.1 cannot attach to iOS Simulator (SOLVED)

    • Press Command+Shift+,

      That is Command, and then Shift and then the <, button on your keyboard.

      Or simply go to Help and then type Edit Scheme and click the item that says Edit Scheme.

      Or again, you can go to the Product menu and find the Edit Scheme menu there.

      While in Edit Scheme window, select the "Run" option on the left hand side of the screen and then on the right hand side, change the debugger from LLDB to GDB.

      I hope this helps

  1. Hi, I’m a newbie in iOS dev. I have too the “attach stuck problem”.
    Is there a problem using GDB permanently instead of LLVM in xcode 4.5 to target iOS6 ? Why use LLVM and not GDB ?

  2. Hey!! I am stuck with a black screen when I try to compile my app!! I then have to force quit Xcode and the Simulator!! Plz Help.

  3. I had this problem with Xcode 4, I always worked switching the debugger from LLVM to GDB, and now with Xcode 5 the GDB debugger doesn’t exist anymore. :S

  4. I have this problem with Xcode 5. I’m testing things out using Apples TicTacToe app (so built for ios 7 etc.) No matter what I try the debugger never attaches to the running app.. Anyone have any ideas?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s