# Python Wrapping build error
**URL:** https://discourse.itk.org/t/python-wrapping-build-error/1335
**Category:** Engineering
**Created:** [October 5, 2018, 11:06pm UTC](https://discourse.itk.org/t/python-wrapping-build-error/1335 "2018-10-05T23:06:57Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@melrobin](https://discourse.itk.org/u/melrobin)
#### Post date: [October 5, 2018, 11:06pm UTC](https://discourse.itk.org/t/python-wrapping-build-error/1335/1 "2018-10-05T23:06:57Z")
I can build ITK from development sources fine, but when I turn on Python wrapping I get a few errors of the sort:
[29%] Generating …/…/itkLevelSetNode.xml
In file included from /home/melrobin/packages/ITK/build/Wrapping/itkLabelContourImageFilter.cxx:16:
In file included from /home/melrobin/packages/ITK/Modules/Filtering/ImageLabel/include/itkLabelContourImageFilter.h:22:
/home/melrobin/packages/ITK/Modules/Filtering/ImageLabel/include/itkScanlineFilterCommon.h:136:16: error:
use of undeclared identifier ‘m\_LineMap’
MapBegin = m\_LineMap.begin();
How can everything build fine, but wrapping cause these errors?
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [October 6, 2018, 2:15pm UTC](https://discourse.itk.org/t/python-wrapping-build-error/1335/2 "2018-10-06T14:15:34Z")
That must have been caused by some recent code refactoring. I will try building with Python wrapping and fix the errors.
> [@melrobin](#):
>
> How can everything build fine, but wrapping cause these errors?
The answer lies in conditional compilation:
>
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [October 6, 2018, 5:13pm UTC](https://discourse.itk.org/t/python-wrapping-build-error/1335/3 "2018-10-06T17:13:34Z")
Does this [patch](http://review.source.kitware.com/#/c/23786/) fix it for you?
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### Author:  [@melrobin](https://discourse.itk.org/u/melrobin)
#### Post date: [October 6, 2018, 8:27pm UTC](https://discourse.itk.org/t/python-wrapping-build-error/1335/4 "2018-10-06T20:27:44Z")
OK, I’m going to give this a short and reply back.
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### Author:  [@melrobin](https://discourse.itk.org/u/melrobin)
#### Post date: [October 6, 2018, 9:39pm UTC](https://discourse.itk.org/t/python-wrapping-build-error/1335/5 "2018-10-06T21:39:16Z")
The patch fixed the build problem.