  We investigate the formation of a new class of density-phase defects in a
resonantly driven 2D quantum fluid of light. The system bistability allows the
formation of low density regions containing density-phase singularities
confined between high density regions. We show that in 1D channels, an odd
(1-3) or even (2-4) number of dark solitons form parallel to the channel axis
in order to accommodate the phase constraint induced by the pumps in the
barriers. These soliton molecules are typically unstable and evolve toward
stationary symmetric or anti-symmetric arrays of vortex streets
straightforwardly observable in \emph{cw} experiments. The flexibility of this
photonic platform allows implementing more complicated potentials such as
maze-like channels, with the vortex streets connecting the entrances and thus
solving the maze.
