Running default QtQuick 1 application fails on Mac when using Clang compiler

Steps to reproduce:

• create a new QtQuick 1 application
• select a kit configure to use a clang compiler
• build and run it

Expected behaviour:

• 'Hello World' example window pops up

Current behaviour:

• inside the Application Output widget I'm getting an endless print of "QMutex::lock(): cv wait failure: Invalid argument" and the window is not shown
• you have to stop the 'run' with the Stop button

Note: This works fine when using gcc compiler instead of clang