$ dpkg -S /usr/share/applications/ubuntu-sdk-ide.desktop
ubuntu-sdk-ide: /usr/share/applications/ubuntu-sdk-ide.desktop
# Calls 'Exec=qtcreator %F'

$ dpkg -S /usr/share/applications/ubuntusdk.desktop
qtcreator-plugin-ubuntu: /usr/share/applications/ubuntusdk.desktop
# Calls 'Exec=/usr/bin/ubuntu-sdk-ide %F'