With libc++ 21, math/vtk9 fails to compile, resulting in errors similar
to:
In file included from /wrkdirs/usr/ports/math/vtk9/work/VTK-9.5.2/ThirdParty/fmt/vtkfmt/src/os.cc:14:
In file included from /wrkdirs/usr/ports/math/vtk9/work/VTK-9.5.2/ThirdParty/fmt/vtkfmt/vtkfmt/os.h:11:
/wrkdirs/usr/ports/math/vtk9/work/VTK-9.5.2/ThirdParty/fmt/vtkfmt/vtkfmt/format.h:747:28: error: use of undeclared identifier 'malloc'
747 | T* p = static_cast<T*>(malloc(n * sizeof(T)));
| ^~~~~~
/wrkdirs/usr/ports/math/vtk9/work/VTK-9.5.2/ThirdParty/fmt/vtkfmt/vtkfmt/format.h:752:35: error: use of undeclared identifier 'free'
752 | void deallocate(T* p, size_t) { free(p); }
| ^~~~
This is because malloc and free are defined in <cstdlib>, which is not
included in vtk's format.h. Add the include to fix the build.
PR: 292590
Approved by: yuri (maintainer)
MFH: 2026Q1
1fe6f24779