ensure errors are not logged when using exception=False

pyomo/core/tests/unit/test_numeric_expr.py

@@ -22,6 +22,8 @@
 
 from filecmp import cmp
 import pyomo.common.unittest as unittest
+from pyomo.common.log import LoggingIntercept
+from io import StringIO
 
 from pyomo.environ import ConcreteModel, AbstractModel, RangeSet, Var, Param, Set, Constraint, ConstraintList, Expression, Objective, Reals, ExternalFunction, PositiveReals, log10, exp, floor, ceil, log, cos, sin, tan, acos, asin, atan, sinh, cosh, tanh, acosh, asinh, atanh, sqrt, value, quicksum, sum_product, is_fixed, is_constant
 from pyomo.kernel import variable, expression, objective
@@ -5244,5 +5246,17 @@ def con_rule(model):
         self.assertEqual(polynomial_degree(m.c1.body), 1)
 
 
+class TestEvaluation(unittest.TestCase):
+    def test_log_error(self):
+        m = ConcreteModel()
+        m.x = Var()
+        e = m.x**2
+        os = StringIO()
+        with LoggingIntercept(os, 'pyomo'):
+            e_val = value(e, exception=False)
+            self.assertIsNone(e_val)
+        self.assertEqual(os.getvalue(), '')
+
+
 if __name__ == "__main__":
     unittest.main()