Parsing of seed_transpiler in generate_preset_pass_manager (backport #12980)

qiskit/transpiler/preset_passmanagers/generate_preset_pass_manager.py

@@ -343,6 +343,7 @@ def generate_preset_pass_manager(
     # Parse non-target dependent pm options
     initial_layout = _parse_initial_layout(initial_layout)
     approximation_degree = _parse_approximation_degree(approximation_degree)
+    seed_transpiler = _parse_seed_transpiler(seed_transpiler)
 
     pm_options = {
         "target": target,
@@ -516,3 +517,11 @@ def _parse_approximation_degree(approximation_degree):
     if approximation_degree < 0.0 or approximation_degree > 1.0:
         raise TranspilerError("Approximation degree must be in [0.0, 1.0]")
     return approximation_degree
+
+
+def _parse_seed_transpiler(seed_transpiler):
+    if seed_transpiler is None:
+        return None
+    if not isinstance(seed_transpiler, int) or seed_transpiler < 0:
+        raise ValueError("Expected non-negative integer as seed for transpiler.")
+    return seed_transpiler

releasenotes/notes/fix-negative-seed-pm-2813a62a020da115.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Fixed the behavior of :meth:`.generate_preset_pass_manager` to raise a `ValueError` exception if not provided with a non-negative integer `seed_transpiler` argument.

test/python/transpiler/test_preset_passmanagers.py

@@ -1511,6 +1511,18 @@ def test_generate_preset_pass_manager_with_list_initial_layout(self, optimizatio
         self.assertIsInstance(pm_object, PassManager)
         self.assertEqual(tqc_list, tqc_obj)
 
+    def test_parse_seed_transpiler_raises_value_error(self):
+        """Test that seed for transpiler is non-negative integer."""
+        with self.assertRaisesRegex(
+            ValueError, "Expected non-negative integer as seed for transpiler."
+        ):
+            generate_preset_pass_manager(optimization_level=1, seed_transpiler=-1)
+
+        with self.assertRaisesRegex(
+            ValueError, "Expected non-negative integer as seed for transpiler."
+        ):
+            generate_preset_pass_manager(seed_transpiler=0.1)
+
 
 @ddt
 class TestIntegrationControlFlow(QiskitTestCase):