@ruffsl the infrastructure for building extensions on GNU/Linux has been updated recently. Some extensions seem to have been affected by this update ( Slicer Build Environment Upgraded to `qt5-almalinux8-gcc14` - #6 by fedorov ). Our colleagues from Kitware are aware of this issue and will check on it soon.
While extensions such as SlicerSOFA and DCMQI seem to fail only in the GNU/Linux build system, some other extension may fail legitimately because they need an update to adapt to the new build system. To test in which case the IGT extensions fall into, it is not enough to build them in your own system. A good test to discriminate whether the extension needs an update or the build system needs and adjustment, you would need to build Slicer and the extensions using Slicer building environment. @ruffsl, would you have the availability to give the extensions a try with GitHub - Slicer/SlicerBuildEnvironment: A repository of scripts to set up a Slicer build environment. using the qt5-almalinux8-gcc14 environment? This would help speeding up the diagnostic and eventual resolution of the problem.