1. Remove Creator's settings from %APPDATA%.
   I assume that Creator will find a kit automatically from PATH or SDK settings.
2. Start Creator.
3. Enable the Qbs plugin.
4. Restart Creator.
5. Open qtcreator.qbs from Creator's repository.
6. Go to Projects mode.
   The displayed build directory contains a redundant "..", e.g.:

   C:\Users\rob\dev\src\creator-3.0\..\qtcreator-build
   

7. Switch the build configuration to "Release".
   Same fault.
8. Switch the build configuration back to "Debug".
   Creator now displays a decent path:

   C:\Users\rob\dev\src\qtcreator-build
   

Creator should display the clean path from the beginning.