Build ITK with unsigned char support for ImageRegistrationMethodv4

I'm trying to run ImageRegistrationMethodv4 in python with a 3d uint8 fixed and moving image but that causes the following error:

`TemplateTypeError: itk.ImageRegistrationMethodv4 is not wrapped for input type "itk.Image[itk.UC,3], itk.Image[itk.UC,3]"`

The message suggested building ITK with support for the requested pixel type so I did this using the options: -DITK_WRAP_PYTHON=ON -DITK_WRAP_unsigned_char=ON
The build is successful, and I can install it, everything seems to work but I still get the same error.

Is it even possible to built ITK with UC3 support for the ImageRegistrationMethodv4 method? Its not clear to me whether the error message is misleading or not.