Problem with building VisIt 3.4.1 from source code conflict between Python-3.9.18.tgz and VTK-8.1.0.tar.gz

[josephhennessey]

Hello,

I have a problem with building VisIt 3.4.1 from source code conflict between Python-3.9.18.tgz and VTK-8.1.0.tar.gz
It seems that VTK-8.1.0 requires Python 3.8.x or older in order to build properly.

In particular

#if PY_VERSION_HEX >= 0x03080000
//Prior to Py3.8, this member was a function pointer,
//but as of Py3.8 it is an integer
//(and therefore incompatible with nullptr).
0, // tp_vectorcall_offset
#else
nullptr, // tp_print
#endif

//to address it

//change files
VTK-8.1.0/Wrapping/Tools/vtkWrapPythonClass.c
VTK-8.1.0/Wrapping/Tools/vtkWrapPythonEnum.c
VTK-8.1.0/Wrapping/Tools/vtkWrapPythonType.c

//from

" nullptr, // tp_print\n"
//to
" 0, // tp_print\n"

//and change instances in these files
VTK-8.1.0/Wrapping/PythonCore/PyVTKNamespace.cxx
VTK-8.1.0/Wrapping/PythonCore/PyVTKTemplate.cxx
VTK-8.1.0/Wrapping/PythonCore/PyVTKReference.cxx
VTK-8.1.0/Wrapping/PythonCore/PyVTKMethodDescriptor.cxx

//from

nullptr, // tp_print

//to

#if PY_VERSION_HEX >= 0x03080000
0, // tp_vectorcall_offset
#else
nullptr, // tp_print
#endif

I cann't see how to build VisIt 3.4.1 without this issue being addressed.

Thanks,

Joe Hennessey

[biagas]

build_visit should be building vtk9, but it requires adding '--qt6' or '--vtk9' to the build_visit command line.
Apologies we didn't get the script fixed so that '--vtk9' wasn't needed before the 3.4.1 release.
Qt 6 is also the preferred version of Qt for 3.4.x, but we experienced problems building it on a couple of systems which is why we still support Qt 5.
Adding '--qt6' will automatically get you vtk 9. If there are problems building qt 6, then just adding '--vtk9' will suffice.

[biagas]

@josephhennessey Did you try with '--qt6' and/or '--vtk9', have you had success building VisIt?