Xcode 5 says "Simulator in Use" when running 64-bit Unit tests

Question

I just downloaded and installed Xcode 5 GM seed. I removed the previous Xcode (DP5). When I open my project, select "iPhone Retina (4-inch 64 bit)" and type Command-U to run my SenTeskingKit unit tests, Xcode invariably complains:

"Simulator in Use - The Simulator can't be launched because it is already in use."

I have run xcode-select to point to the new Xcode, restarted my MacBookPro, and made sure there are no other iPhone sim processes running under the Activity Monitor.

Answer 1

With Xcode 5 Version 5.0 (5A1413), I cannot run 64-bit unit tests at all. Always gives a "Simulator in use" error alert.

Quitting Xcode or the Simulator does not help.

My "solution", thanks to this question, is to run the tests against the 32-bit simulator.