--- VTK-8.2.0/Utilities/Python/CMakeLists.txt.orig	2019-05-22 15:09:47.607021700 +0300
+++ VTK-8.2.0/Utilities/Python/CMakeLists.txt	2019-05-22 15:10:29.029079800 +0300
@@ -28,7 +28,7 @@
 # Export location of python module dirs in install and build tree for every vtkpython module to use
 # As long as those modules depend on vtkpython, they can retrieve and use these
 if(NOT VTK_PYTHON_SITE_PACKAGES_SUFFIX)
-  if(WIN32 AND NOT CYGWIN)
+  if(MSVC)
     set(VTK_PYTHON_SITE_PACKAGES_SUFFIX "Lib/site-packages")
   else()
     set(VTK_PYTHON_SITE_PACKAGES_SUFFIX
@@ -52,7 +52,7 @@
 endif()
 
 if(NOT DEFINED VTK_INSTALL_PYTHON_MODULES_DIR)
-  if(WIN32 AND NOT CYGWIN)
+  if(MSVC)
     set(VTK_INSTALL_PYTHON_MODULES_DIR
       "${VTK_INSTALL_RUNTIME_DIR}/${VTK_PYTHON_SITE_PACKAGES_SUFFIX}"
       CACHE INTERNAL "Directory where python modules will be installed")
--- VTK-8.2.0/ThirdParty/xdmf2/vtkxdmf2/CMake/setup_install_paths.py.orig	2019-05-22 15:14:18.614402100 +0300
+++ VTK-8.2.0/ThirdParty/xdmf2/vtkxdmf2/CMake/setup_install_paths.py	2019-05-22 15:15:06.457469200 +0300
@@ -16,6 +16,7 @@
 import string
 import sys
 import os
+from sysconfig import _POSIX_BUILD
 
 def get_install_path(command, *args):
     """Return the module install path, given the arguments that were
@@ -84,7 +85,7 @@
         platlib = home+'/lib/python'
         scripts = home+'/bin'
         data    = home
-    elif os.name == 'posix':
+    elif os.name == 'posix' or _POSIX_BUILD:
         ver = sys.version[0:3]
         purelib = prefix+'/lib/python'+ver+'/site-packages'
         platlib = exec_prefix+'/lib/python'+ver+'/site-packages'
--- VTK-8.2.0/CMake/FindPythonLibs.cmake.orig	2019-01-30 18:15:13.000000000 +0100
+++ VTK-8.2.0/CMake/FindPythonLibs.cmake	2021-01-03 10:14:54.693475800 +0100
@@ -32,7 +32,7 @@
 # Use the executable's path as a hint
 set(_Python_LIBRARY_PATH_HINT)
 if(PYTHON_EXECUTABLE)
-  if(WIN32)
+  if(MSVC)
     get_filename_component(_Python_PREFIX ${PYTHON_EXECUTABLE} PATH)
     if(_Python_PREFIX)
       set(_Python_LIBRARY_PATH_HINT ${_Python_PREFIX}/libs)
@@ -70,11 +70,11 @@
 # the user supplied additional versions to the front.
 set(_Python_VERSIONS
   ${Python_ADDITIONAL_VERSIONS} ${_PythonInterp_VERSION}
-  2.7 2.6 2.5 3.6 3.5 3.4 3.3 3.2)
+  2.7 2.6 2.5 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2)
 
 foreach(_CURRENT_VERSION ${_Python_VERSIONS})
   string(REPLACE "." "" _CURRENT_VERSION_NO_DOTS ${_CURRENT_VERSION})
-  if(WIN32)
+  if(MSVC)
     find_library(PYTHON_DEBUG_LIBRARY
       NAMES python${_CURRENT_VERSION_NO_DOTS}_d python
       HINTS ${_Python_LIBRARY_PATH_HINT}
@@ -102,10 +102,6 @@
       python${_CURRENT_VERSION}
     HINTS
       ${_Python_LIBRARY_PATH_HINT}
-    PATHS
-      ${PYTHON_FRAMEWORK_LIBRARIES}
-      [HKEY_LOCAL_MACHINE\\SOFTWARE\\Python\\PythonCore\\${_CURRENT_VERSION}\\InstallPath]/libs
-      [HKEY_CURRENT_USER\\SOFTWARE\\Python\\PythonCore\\${_CURRENT_VERSION}\\InstallPath]/libs
     # Avoid finding the .dll in the PATH.  We want the .lib.
     NO_SYSTEM_ENVIRONMENT_PATH
   )