  We present an exact full symmetry analysis of the 0-$\pi$ superconducting
circuit. We identify points in control parameter space of enhanced anomalous
symmetry, which imposes robust twofold degeneracy of its ground state, that is
for all values of the energy parameters of the model. We show, both
analytically and numerically, how this anomalous symmetry is maintained in the
low-energy sector, thus providing us with a strong candidate for robust qubit
engineering.
