From a6438bad0ddb80fb563c640084f3b8b2a78ba9f9 Mon Sep 17 00:00:00 2001
From: Jason Krizan <34923517+orthorhombic@users.noreply.github.com>
Date: Sun, 18 Aug 2024 20:26:47 -0400
Subject: [PATCH 1/2] Change from %r to %s for NumPy 2.0 compatibility

---
 pyomo/repn/plugins/nl_writer.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyomo/repn/plugins/nl_writer.py b/pyomo/repn/plugins/nl_writer.py
index 8f51f0b0fba..0b24ff34245 100644
--- a/pyomo/repn/plugins/nl_writer.py
+++ b/pyomo/repn/plugins/nl_writer.py
@@ -2365,7 +2365,7 @@ class text_nl_debug_template(object):
     # NOTE: to support scaling and substitutions, we do NOT include the
     # 'v' or the EOL here:
     var = '%s'
-    const = 'n%r\n'
+    const = 'n%s\n'
     string = 'h%d:%s\n'
     monomial = product + const + var.replace('%', '%%')
     multiplier = product + const

From f3a07ed6de0f847138458c6c3c45689289bc6fc9 Mon Sep 17 00:00:00 2001
From: John Siirola <jsiirola@users.noreply.github.com>
Date: Mon, 19 Aug 2024 14:07:43 -0600
Subject: [PATCH 2/2] Add test for #3352

---
 pyomo/repn/tests/ampl/test_nlv2.py | 32 ++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/pyomo/repn/tests/ampl/test_nlv2.py b/pyomo/repn/tests/ampl/test_nlv2.py
index 0bfdb22a2ba..35030caeb52 100644
--- a/pyomo/repn/tests/ampl/test_nlv2.py
+++ b/pyomo/repn/tests/ampl/test_nlv2.py
@@ -2761,6 +2761,38 @@ def test_nested_external_expressions(self):
 0 0
 1 0
 2 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    @unittest.skipUnless(numpy_available, "test requires numpy")
+    def test_objective_numpy_const(self):
+        # This tests issue #3352
+        m = ConcreteModel()
+        m.e = Expression(expr=numpy.float64(0))
+        m.obj = Objective(expr=m.e)
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(m, OUT, linear_presolve=False, scale_model=True)
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	#problem unknown
+ 0 0 1 0 0     #vars, constraints, objectives, ranges, eqns
+ 0 0 0 0 0 0   #nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0   #network constraints: nonlinear, linear
+ 0 0 0 #nonlinear vars in constraints, objectives, both
+ 0 0 0 1       #linear network variables; functions; arith, flags
+ 0 0 0 0 0     #discrete variables: binary, integer, nonlinear (b,c,o)
+ 0 0   #nonzeros in Jacobian, obj. gradient
+ 0 0   #max name lengths: constraints, variables
+ 0 0 0 0 0     #common exprs: b,c,o,c1,o1
+O0 0
+n0
+x0
+r
+b
+k-1
 """,
                 OUT.getvalue(),
             )