Howto do a clean uninstall and reinstall of qt sdk
From Qt Wiki
Uninstall and Reinstall QtSDK on Mac system
- sudo QtSDK/SDKMaintenanceTool.app/Contents/MacOS/SDKMaintenanceTool
- In newer versions replace both instances of SDKMaintenanceTool with MaintenanceTool.
- If not QtSDK, check for /Users/YourUserName/QtX.Y.Z where X.Y.Z is a Qt version.
- The tool's dialog window will show up. In the dialog window select "Remove all components".
- Click the Continue button, the the Uninstall button to confirm. Qt SDK will be uninstalled and QtSDK directory will be removed.
- Run the QtSDK installer if reinstallation is needed.
- In the installation dialog window, make sure to check the box "Remove the old Qt Creator's setting".
- Continue to finish the installation.