# Wrap\_python build error in qt loadable widget

**URL:** <https://discourse.slicer.org/t/wrap-python-build-error-in-qt-loadable-widget/37298>\
**Category:** Support\
**Created:** [July 10, 2024, 8:21am UTC](https://discourse.slicer.org/t/wrap-python-build-error-in-qt-loadable-widget/37298 "2024-07-10T08:21:31Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![fqzhice](https://avatars.discourse-cdn.com/v4/letter/f/7bcc69/32.png) [@fqzhice](https://discourse.slicer.org/u/fqzhice)\
**Post date:** [July 10, 2024, 8:21am UTC](https://discourse.slicer.org/t/wrap-python-build-error-in-qt-loadable-widget/37298/1 "2024-07-10T08:21:31Z")

</div>

Hi,

```
In custom qt loadable extension, I set "WRAP_PYTHON" and include "ctkDICOMDisplayedFieldGeneratorRuleFactory".

```

I found this class is singleton and generate wrapper itself

```auto
private:
 ...
  friend class PythonQtWrapper_ctkDICOMDisplayedFieldGeneratorRuleFactory; // Allow Python wrapping without enabling direct instantiation

```

but , in generated\_cpp folder , the xxxxPythonQt project build fails becasue the constructer ctkDICOMDisplayedFieldGeneratorRuleFactory is private

```auto
class PythonQtWrapper_ctkDICOMDisplayedFieldGeneratorRuleFactory : public QObject
{
...
  ctkDICOMDisplayedFieldGeneratorRuleFactory* new_ctkDICOMDisplayedFieldGeneratorRuleFactory(QObject* parent = 0)
    {
    return new ctkDICOMDisplayedFieldGeneratorRuleFactory(parent);
    }
...
};

```

can anyone help to solve it?