diff -up ParaView-v5.8.1/VTK/ThirdParty/freetype/vtk_freetype.h.in.freetype ParaView-v5.8.1/VTK/ThirdParty/freetype/vtk_freetype.h.in
--- ParaView-v5.8.1/VTK/ThirdParty/freetype/vtk_freetype.h.in.freetype 2020-10-31 08:59:37.251895020 -0600
+++ ParaView-v5.8.1/VTK/ThirdParty/freetype/vtk_freetype.h.in 2020-10-31 09:00:38.592349496 -0600
@@ -25,6 +25,15 @@
#if VTK_MODULE_USE_EXTERNAL_vtkfreetype
# include <ft2build.h>
+/* FT_CALLBACK_DEF no longer exported since freetype-2.10.3 */
+/* has been moved to <freetype/internal/compiler-macros.h> */
+# ifndef FT_CALLBACK_DEF
+# ifdef __cplusplus
+# define FT_CALLBACK_DEF( x ) extern "C" x
+# else
+# define FT_CALLBACK_DEF( x ) static x
+# endif
+# endif /* FT_CALLBACK_DEF */
#else
# include <vtkfreetype/include/ft2build.h>
#endif