Add test case: test_error_message_without_previous_definition_location

Author: cchung100m

tests/python/tir-analysis/test_tir_analysis_verify_well_formed.py

@@ -345,5 +345,35 @@ def func():
     tvm.tir.analysis.verify_well_formed(mod)
 
 
+def test_error_message_without_previous_definition_location():
+    """Test case 1: Error message without 'It was first defined at'
+
+    This tests the scenario where it == end(), so the error message should contain
+    'TIR is ill-formed, due to multiple definitions of variable' but should NOT
+    contain 'It was first defined at' since the iterator is invalid.
+    """
+
+    @I.ir_module(check_well_formed=False)
+    def func_variable_not_in_previous_map():
+        x = T.int32()
+
+        with T.LetStmt(42, var=x):
+            T.evaluate(x)
+
+
+        with T.LetStmt(99, var=x):  # This should trigger the error
+            T.evaluate(x)
+
+
+    with pytest.raises(ValueError) as exc_info:
+        tvm.tir.analysis.verify_well_formed(func_variable_not_in_previous_map, assert_mode=True)
+
+  
+    error_msg = str(exc_info.value)
+
+    assert "TIR is ill-formed" in error_msg
+    assert "multiple definitions of variable" in error_msg
+
+
 if __name__ == "__main__":
     tvm.testing.main()