macOS Xcode Build/Run problem

[Basibo1]

I've installed Xcode 4.2.1 on Mac OS X Lion.
When I create a new (Mac OS X Cocoa) project and I click "Run", Xcode says build succeeded, but doesn't run the project. No errors, but no application either.
When I do exactly the same thing on another Mac (but with OS X Snow Leopard and Xcode 4.0.1 installed), the created app starts bouncing in the dock and shows an empty window, like I would expect.
When I look in the Console, there seems to be nothing strange going on.
I tried reinstalling Xcode, deleting everything related to Xcode, but still no luck.
Anyone got an idea what could be the problem?

Thanks in advance,

Basibo1

 

[AxiomaticRubric]

I'm not 100% certain but this might be a new feature in Xcode 4.2. Try putting some generic content in a XIB file (making sure it's properly referenced in a view controller, etc.) and see if running the app opens the simulator. If this doesn't bring up the simulator then you've got something else going on.

 

[Basibo1]

Nope, that didn't work either. Still no window showing up.
Thanks for the help

 

[Basibo1]

In the scheme, the debugger was set to GDB, it should've been LLDB. Now the app runs fine.

 

[jiminaus]

In the scheme, the debugger was set to GDB, it should've been LLDB. Now the app runs fine.

You've got a really nasty, salient bug if your program works under LLDB but not GDB. Any well-behaved program should run equally well under either, and neither.

 

[Basibo1]

Yeah that's strange, but I'm really happy it works now