By using local systems over simplicial sets with values in differential graded algebras, we consider a framework of rational and R-local homotopy theory for diffeological spaces with arbitrary fundamental groups. Moreover, a spectral sequence converging to the singular de Rham cohomology of an adjunction space is constructed with the pullback of local systems. In case of a stratifold obtained by attaching manifolds, the spectral sequence converges to the original de Rham cohomology, which is due to Souriau, of the stratifold.