Crash in WLMP when step is not present

The compiler crashes for the following program when a step size of [1, 1] is not explicitly given:

int main()
{
    return with {
        ([0, 0] <= iv < [4, 4]):  _aplmod_SxS_ (iv[0] + 1, 2);
    } : fold (+, 0);
}

When SetSRPstep() in wl_modulo_partitioning.c is called, it creates a step if no step exists yet.
Creating the step results in an N_array, but it expects itself to create an N_avis of an array, causing the crash.