[Debian-med-packaging] Bug#1145144: FTBFS due to HDF5 required by both VTK and ITK

[Manik Bhattacharjee]

Thank you for the bug report.
After some investigation we found out this is due to a change in the 
latest ITK and VTK packages that now require HDF5 in two incompatible ways.
ITK uses the standard path of FindHDF5.cmake, VTK a custom patch based 
on an older version.

  /usr/lib/x86_64-linux-gnu/cmake/vtk-9.6/patches/99/FindHDF5.cmake
  /usr/share/cmake-4.3/Modules/FindHDF5.cmake

A minimal CMakeLists.txt file can reproduce the issue without camitk:

cmake_minimum_required(VERSION 3.28)
project(HDF5Issue)
# FIX: find_package(HDF5 COMPONENTS C HL)
find_package(VTK REQUIRED COMPONENTS CommonCore)
find_package(ITK REQUIRED)

Calling "cmake -S . -B build" in the directory containing this file will show the conflict.

Bug #1147167 has been posted to VTK9 package to explain the issue in more detail : https://bugs.debian.org/1147167

A workaround is being implemented as a patch to the package but there are still some issues with it that will hopefully be resolved soon.

M%anik Bhattacharjee