Put the gelatin into a small bowl, drain the pineapple juice over it, stir to dissolve, set aside.
Bring the cranberry sauce, pineapple flesh, lemon gelatin, and lemon juice, to a boil with a pinch of salt. Simmer about 1 minute. Remove from heat. Stir in softened gelatin till smooth. Add ginger ale, stir in pecans. Cool to room temperature.
Grease, with vegetable oil, a 3-4 cup mold and chill this mixture for 6 hours or overnight.
Note: the pecans may sink a little while the mold chills, if it is essential to you that they remain evenly dispersed, chill the gel, in the saucepan, until it thickens lightly, but not so far to the point, that it becomes chunky or coarse, then stir in the nuts, and pack into the greased mold.