Bring the sugar, vinegar, and salt to a boil in a large nonreactive saucepan over high heat. Reduce the heat to medium and cook until reduced by half, about 10 minutes.
Stir in the tomatoes, onion, garlic, ginger, and chipotle powder. Simmer until thickened, stirring often, about 30 minutes. Stir in the raisins and almonds. Cool, cover, and refrigerate until ready to serve.