1) In a medium mixing bowl combine the rhubarb, sugar, and cinnamon, mixing well to coat. Let stand stirring occasionally. 2) After about ten to fifteen min. add the pie filling, spice, and tapioca to the rhubarb mixture and mix well... 3) Place the bottom pastry into the pie dish pressing into all of the corners, then add the fruit and cover with the remaining pastry, sealing and fluting the edges... 4) Bake in a pre-heated 325o oven for 35 to 40 min. and let cool completely before serving... Note... Graham cracker, shortbread, and chocolate cookie (prepared) pie crusts do not work at all well with this recipe...