Creator mistakes project built with Qt5 for different project

1. Set up a Qt5 Kit in Creator.
   I used:

   Compiler	Microsoft Windows SDK for Windows 7 (7.1.7600.0.30514) (x86)
   Qt version	Qt 5.0.0 beta2 MSVC2010 32 bit (SDK)

2. Create or open a project.
3. Configure the project for the Kit from step 1.
4. Build the project.
5. Go to Projects mode.
6. See the Build directory.
   The path is written in red letters and Creator shows the warning: "A build for a different project exists in <PATH>, which will be overwritten." This build resulted from this very project, built with this very Kit.

Instead, Creator should identify Qt5 builds correctly.