)(available, count), str);
// if we still have buffered input update gptr
if (available > count)
{
```
b. Link errors:
```auto
FAILED: [code=4294967295] bin/vtkWrappingPythonCore3.13-pv6.1d.dll lib/vtkWrappingPythonCore3.13-pv6.1d.lib
C:\WINDOWS\system32\cmd.exe /C "cd . && "C:\Program Files\CMake\bin\cmake.exe" -E vs_link_dll --msvc-ver=1944 --intdir=VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100261~1.0\x86\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100261~1.0\x86\mt.exe --manifests -- C:\PROGRA~1\MICROS~4\2022\PROFES~1\VC\Tools\MSVC\1444~1.352\bin\Hostx86\x86\link.exe /nologo VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKEnum.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKExtras.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKNamespace.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKObject.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKSpecialObject.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKTemplate.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonArgs.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonCommand.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonOverload.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonUtil.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkSmartPyObject.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKMethodDescriptor.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKReference.cxx.obj /out:bin\vtkWrappingPythonCore3.13-pv6.1d.dll /implib:lib\vtkWrappingPythonCore3.13-pv6.1d.lib /pdb:bin\vtkWrappingPythonCore3.13-pv6.1d.pdb /dll /version:6.1 /machine:X86 /debug /INCREMENTAL lib\vtkCommonCore-pv6.1d.lib lib\vtksys-pv6.1d.lib ws2_32.lib dbghelp.lib psapi.lib lib\vtkfmt-pv6.1d.lib lib\vtkscn-pv6.1d.lib lib\vtktoken-pv6.1d.lib "C:\Program Files\Python313\libs\python313.lib" kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ."
LINK Pass 1: command "C:\PROGRA~1\MICROS~4\2022\PROFES~1\VC\Tools\MSVC\1444~1.352\bin\Hostx86\x86\link.exe /nologo VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKEnum.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKExtras.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKNamespace.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKObject.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKSpecialObject.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKTemplate.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonArgs.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonCommand.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonOverload.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkPythonUtil.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\vtkSmartPyObject.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKMethodDescriptor.cxx.obj VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir\PyVTKReference.cxx.obj /out:bin\vtkWrappingPythonCore3.13-pv6.1d.dll /implib:lib\vtkWrappingPythonCore3.13-pv6.1d.lib /pdb:bin\vtkWrappingPythonCore3.13-pv6.1d.pdb /dll /version:6.1 /machine:X86 /debug /INCREMENTAL lib\vtkCommonCore-pv6.1d.lib lib\vtksys-pv6.1d.lib ws2_32.lib dbghelp.lib psapi.lib lib\vtkfmt-pv6.1d.lib lib\vtkscn-pv6.1d.lib lib\vtktoken-pv6.1d.lib C:\Program Files\Python313\libs\python313.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTFILE:VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir/intermediate.manifest VTK\Wrapping\PythonCore\CMakeFiles\WrappingPythonCore.dir/manifest.res" failed (exit code 1120) with the following output:
Creating library lib\vtkWrappingPythonCore3.13-pv6.1d.lib and object lib\vtkWrappingPythonCore3.13-pv6.1d.exp
PyVTKReference.cxx.obj : error LNK2001: unresolved external symbol __imp___ Py_Dealloc
vtkPythonOverload.cxx.obj : error LNK2001: unresolved external symbol __imp___ Py_Dealloc
vtkPythonUtil.cxx.obj : error LNK2001: unresolved external symbol __imp___ Py_Dealloc
vtkSmartPyObject.cxx.obj : error LNK2001: unresolved external symbol __imp___ Py_Dealloc
PyVTKMethodDescriptor.cxx.obj : error LNK2001: unresolved external symbol __imp___ Py_Dealloc
PyVTKSpecialObject.cxx.obj : error LNK2001: unresolved external symbol __imp___ Py_Dealloc
…
```
I tried the following, none of which fixed the problem:
- checked “python” cmake option, which wasn’t on by default (other python-related options were on)
- Uninstalled python 3.13, installed 3.14
- Disabled VTK\_MODULE\_ENABLE\_VTK\_WrappingPythonCore
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 24, 2026, 4:53pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/4 "2026-03-24T16:53:24Z")
> [@Tim\_Tautges](#):
>
> If viskores doesn’t build out of the box, either it should be disabled by default or whatever dependency is missing should be stated.
Agreed, please open an issue.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 24, 2026, 4:54pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/5 "2026-03-24T16:54:29Z")
Please share your full cmake configuration line, I’m able to build ParaView on Windows with VS2022 without issues here.
---
### Author:  [@Tim\_Tautges](https://discourse.paraview.org/u/Tim_Tautges)
#### Post date: [March 24, 2026, 7:46pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/6 "2026-03-24T19:46:31Z")
cmake -G Ninja -DPARAVIEW\_USE\_VISKORES=NO -DVTK\_MODULE\_ENABLE\_VTK\_vtkviskores=NO -DPARAVIEW\_USE\_PYTHON=YES -DCMAKE\_BUILD\_TYPE=Release ..
---
### Author:  [@Tim\_Tautges](https://discourse.paraview.org/u/Tim_Tautges)
#### Post date: [March 24, 2026, 7:56pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/7 "2026-03-24T19:56:07Z")
Second subject: instructions for building binary-compatible plugin support fail also. cmake line and result are:
```auto
C:\Users\ttautges\ans\pv\build>cmake -G Ninja -C c:\users\ttautges\ans\pv\pv-superbuild\paraview-plugin-windows-binary-compatible-guide\configurations\config_v6.0.1.cmake -Dparaview_SOURCE_DIR=c:\users\ttautges\ans\pv\pv-git -DCMAKE_BUILD_TYPE=Release ..\pv-superbuild
loading initial cache file c:\users\ttautges\ans\pv\pv-superbuild\paraview-plugin-windows-binary-compatible-guide\configurations\config_v6.0.1.cmake
-- The C compiler identification is MSVC 19.44.35225.0
-- The CXX compiler identification is MSVC 19.44.35225.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/Program Files/Microsoft Visual Studio/2022/Professional/VC/Tools/MSVC/14.44.35207/bin/Hostx86/x86/cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/Program Files/Microsoft Visual Studio/2022/Professional/VC/Tools/MSVC/14.44.35207/bin/Hostx86/x86/cl.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Check size of void*
-- Check size of void* - done
CMake Error at superbuild/cmake/SuperbuildUtils.cmake:83 (message):
32-bit targets are not supported.
Call Stack (most recent call first):
superbuild/CMakeLists.txt:56 (superbuild_detect_64bit_target)
-- Configuring incomplete, errors occurred!
```
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 25, 2026, 8:49am UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/8 "2026-03-25T08:49:13Z")
Are you building with a 32bit msvc ?
Definitely not supported and not tested. Use 64bit toolchain.
---
### Author:  [@Tim\_Tautges](https://discourse.paraview.org/u/Tim_Tautges)
#### Post date: [March 25, 2026, 3:22pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/9 "2026-03-25T15:22:53Z")
My msvc has both 32 and 64 bit capability installed, cmake is choosing 32 bit for some reason.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 25, 2026, 3:28pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/10 "2026-03-25T15:28:35Z")
Use the “Native x64 MSVC command line tool” to run cmake and cmake --build. You will avoid all issues.
Here is the compilation guide: [https://gitlab.kitware.com/paraview/paraview/-/blob/master/Documentation/dev/build.md?ref\_type=heads#windows](https://gitlab.kitware.com/paraview/paraview/-/blob/master/Documentation/dev/build.md?ref_type=heads#windows)
---
### Author:  [@Tim\_Tautges](https://discourse.paraview.org/u/Tim_Tautges)
#### Post date: [March 25, 2026, 3:44pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/11 "2026-03-25T15:44:44Z")
Good spot, I didn’t realize there was a 64 bit native command tool. But, same result:
Edit: hold on, didn’t clear the cache, maybe that’s it…
Ok, got past that point, so moving forward. Thanks a bunch for the timely help.
---
### Author:  [@Tim\_Tautges](https://discourse.paraview.org/u/Tim_Tautges)
#### Post date: [March 25, 2026, 9:01pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/12 "2026-03-25T21:01:39Z")
> [@Tim\_Tautges](#):
>
> ```auto
> cmake -G Ninja -C c:\users\ttautges\ans\pv\pv-superbuild\paraview-plugin-windows-binary-compatible-guide\configurations\config_v6.0.1.cmake -Dparaview_SOURCE_DIR=c:\users\ttautges\ans\pv\pv-git -DCMAKE_BUILD_TYPE=Release ..\pv-superbuild
> loading initial cache file c:\users\ttautges\ans\pv\pv-superbuild\paraview-plugin-windows-binary-compatible-guide\configurations\config_v6.0.1.cmake
>
> ```
Getting close with superbuild build. It’s stopping on the following:
```auto
-- VTK version: 9.6.0.rc3-5-g4f28f0202d
CMake Error at CMakeLists.txt:738 (message):
The following modules were requested or required, but not found:
VTK::doubleconversion.
-- Configuring incomplete, errors occurred!
CMake Error at C:/Users/ttautges/ans/pv/build/superbuild/sb-paraview-configure.cmake:48 (message):
Failed with exit code 1
```
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 30, 2026, 8:01am UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/13 "2026-03-30T08:01:20Z")
Which version (as in “git commit”) of ParaView are you building ?
---
### Author:  [@Tim\_Tautges](https://discourse.paraview.org/u/Tim_Tautges)
#### Post date: [March 30, 2026, 4:00pm UTC](https://discourse.paraview.org/t/unable-to-build-6-1-0-rc1-on-windows/17490/14 "2026-03-30T16:00:49Z")
> [@Tim\_Tautges](#):
>
> ```auto
> The following modules were requested or required, but not found:
> VTK::doubleconversion.
>
> ```
In the end, working from paraview release 6.0.1-RC2, the build worked once I used the 64bit native shell. Thanks a bunch for your help.