have you also tried this solution? https://v-play.net/developers/forums/t/demo-applications-runs-wo-graphics/#post-5084 . We’ll add official Ubuntu 13 support, including a proper installation guide, with our next major release. Please keep me updated if this solution works for you!
Regarding “linux-g++”, which version of Qt Creator are you using currently (as the flag should already be set by Qt Creator automatically)?