1. Install Qt Creator from an official offline installer.
   I used Qt Creator 4.13 beta2 enterprise.
   The installer creates the menu entry file org.qt-project.qtcreator.desktop in /home/$USER/.local/share/applications
2. Install Qt Creator again from another official offline installer.
   I used Qt Creator 4.13 beta2 opensource.
   The installer moves the menu entry file from the previous step to a temporary file, e.g. org.qt-project.qtcreator.desktop.tmp.l7cgJ.1, and creates its own org.qt-project.qtcreator.desktop.
3. Uninstall the Qt Creator from step 1 using the QtCreatorUninstaller.
   The Uninstaller removes the menu entry file of the other installation and leaves the temporary file behind.
4. Uninstall the Qt Creator from step 2 using the QtCreatorUninstaller.
   The Uninstaller moves the temporary file back to org.qt-project.qtcreator.desktop. This points to the already removed installation from step 1 and will not be removed anymore.

After installing and uninstalling a couple of times, this will leave quite a number of garbage files behind in your applications directory.

The Uninstaller should make sure that it removes the right .desktop file.