Throw exception for infeasible models

src/model/solve.jl

@@ -38,8 +38,7 @@ function solve(
     JuMP.optimize!(model)
 
     if !has_values(model)
-        @warn "No solution available"
-        return OrderedDict()
+        error("No solution available")
     end
 
     if marginal_costs

test/model/solve_test.jl

@@ -38,7 +38,7 @@ end
     for (location_name, location_dict) in json["products"]["P1"]["initial amounts"]
         location_dict["amount (tonne)"] *= 1000
     end
-    RELOG.solve(RELOG.parse(json))
+    @test_throws ErrorException("No solution available") RELOG.solve(RELOG.parse(json))
 end
 
 @testset "solve (with storage)" begin