[vtkusers] Python 3.5 build failures

[Matthias Blaicher]

Hi David,

thanks, that helps. However, I think I now found a Python 3.5 issue:

> /home/mabl/aur/vtk/src/vtk/Wrapping/Python/vtkPythonAppInit.cxx: In function ‘int main(int, char**)’:
> /home/mabl/aur/vtk/src/vtk/Wrapping/Python/vtkPythonAppInit.cxx:167:42: error: ‘_Py_char2wchar’ was not declared in this scope
>    argv0 = _Py_char2wchar(av0.c_str(), NULL);
>                                           ^
> Wrapping/Python/CMakeFiles/vtkpython.dir/build.make:62: recipe for target 'Wrapping/Python/CMakeFiles/vtkpython.dir/vtkPythonAppInit.cxx.o' failed
> make[2]: *** [Wrapping/Python/CMakeFiles/vtkpython.dir/vtkPythonAppInit.cxx.o] Error 1
> CMakeFiles/Makefile2:53236: recipe for target 'Wrapping/Python/CMakeFiles/vtkpython.dir/all' failed

Looks like _Py_char2wchar is inofficial API and got renamed to
Py_DecodeLocale, see
> https://bugs.python.org/issue18395

Very best and thank you for your work!

Matthias

On 10/04/2015 11:03 PM, David Gobbi wrote:
> Hi Matthias,
> 
> Thanks for the report.  It looks like the vtkPythonInterpreter module (which
> is optional and not needed for the Python wrappers) was not updated for
> Python3.  I'll get this fixedASAP, but you can turn this module off as a
> temporary work around.
> 
> This isn't related to Python 3.5, this particular module doesn't build with
> Python 3.4 either.
> 
> Ben, can you add Module_vtkPythonInterpreter:BOOL=ON to the Python3
> dashboard builds?
> 
>  - David
> 
> 
> On Sun, Oct 4, 2015 at 2:30 PM, Matthias Blaicher <matthias at blaicher.com
> <mailto:matthias at blaicher.com>> wrote:
> 
>     Hi,
> 
>     I've just tried to build the master and release-6.3, both fail to build
>     for me. However, it used to work some weeks ago. In that time Arch Linux
>     switched to Python 3.5. Is the current master branch expected to build
>     against Python 3.5?
> 
>     > In file included from
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:21:0:
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: invalid conversion from ‘char*’ to ‘Py_ssize_t {aka long
>     int}’ [-fpermissive]
>     >  };
>     >  ^
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: invalid conversion from ‘PyObject* (*)(PyObject*, PyObject*)
>     {aka _object* (*)(_object*, _object*)}’ to ‘setattrofunc {aka int
>     (*)(_object*, _object*, _object*)}’ [-fpermissive]
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: cannot convert ‘int (*)(PyObject*, PyObject*, PyObject*) {aka
>     int (*)(_object*, _object*, _object*)}’ to ‘PyBufferProcs*’ in
>     initialization
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: invalid conversion from ‘long unsigned int’ to ‘const char*’
>     [-fpermissive]
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: cannot convert ‘char*’ to ‘traverseproc {aka int
>     (*)(_object*, int (*)(_object*, void*), void*)}’ in initialization
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: cannot convert ‘PyMethodDef*’ to ‘PyMemberDef*’ in initialization
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: cannot convert ‘PyMemberDef*’ to ‘PyGetSetDef*’ in initialization
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonStdStreamCaptureHelper.h:144:1:
>     error: invalid conversion from ‘PyObject* (*)(PyTypeObject*,
>     PyObject*, PyObject*) {aka _object* (*)(_typeobject*, _object*,
>     _object*)}’ to ‘freefunc {aka void (*)(void*)}’ [-fpermissive]
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:
>     In function ‘void {anonymous}::vtkPrependPythonPath(const char*)’:
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:64:54:
>     error: ‘PyString_FromString’ was not declared in this scope
>     >      PyObject* newpath = PyString_FromString(pathtoadd);
>     >                                                       ^
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:
>     In static member function ‘static void
>     vtkPythonInterpreter::SetProgramName(const char*)’:
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:191:42:
>     error: cannot convert ‘char*’ to ‘wchar_t*’ for argument ‘1’ to
>     ‘void Py_SetProgramName(wchar_t*)’
>     >      Py_SetProgramName(pool.Strings.back());
>     >                                           ^
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:
>     In static member function ‘static int
>     vtkPythonInterpreter::PyMain(int, char**)’:
>     >
>     /home/mabl/aur/vtk/src/vtk/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:228:28:
>     error: cannot convert ‘char**’ to ‘wchar_t**’ for argument ‘2’ to
>     ‘int Py_Main(int, wchar_t**)’
>     >    return Py_Main(argc, argv);
>     >                             ^
>     >
>     Utilities/PythonInterpreter/CMakeFiles/vtkPythonInterpreter.dir/build.make:72:
>     recipe for target
>     'Utilities/PythonInterpreter/CMakeFiles/vtkPythonInterpreter.dir/vtkPythonInterpreter.cxx.o'
>     failed
>     > make[2]: ***
>     [Utilities/PythonInterpreter/CMakeFiles/vtkPythonInterpreter.dir/vtkPythonInterpreter.cxx.o]
>     Error 1
>     > CMakeFiles/Makefile2:38331: recipe for target
>     'Utilities/PythonInterpreter/CMakeFiles/vtkPythonInterpreter.dir/all' failed
>     > make[1]: ***
>     [Utilities/PythonInterpreter/CMakeFiles/vtkPythonInterpreter.dir/all] Error
>     2
>     > make[1]: *** Waiting for unfinished jobs....
> 
>     Very best,
>     Matthias
>