Bug#1141884: libvtk9.x ships python library without proper shlibs

[Adrian Bunk]

Control: reassign -1 dh-python
Control: forcemerge 1141379 -1
Control: affects 1141379 src:vtk9 python3-vtk9

On Sun, Jul 12, 2026 at 10:57:12AM +0200, Emilio Pozuelo Monfort wrote:
> Source: vtk9
> Version: 9.5.2+dfsg4-5
> Severity: serious
> 
> Hi,
> 
> During the python3.14 as default python3 interpreter transition, vtk9 has
> been binNMU'ed, resulting in the package building
> libvtkWrappingPythonCore3.14-9.5.so.1. However that can cause rdeps to fail,
> as demonstrated in one autopkgtest [1]:
> 
> 332s ERROR: TestFemApp (unittest.loader._FailedTest.TestFemApp)
> 332s ----------------------------------------------------------------------
> 332s ImportError: Failed to import test module: TestFemApp
> 332s Traceback (most recent call last):
> 332s   File "/usr/lib/python3.13/unittest/loader.py", line 137, in loadTestsFromName
> 332s     module = __import__(module_name)
> 332s   File "/usr/share/freecad/Mod/Fem/TestFemApp.py", line 33, in <module>
> 332s     from femtest.app.test_mesh import TestMeshCommon as FemTest07
> 332s   File "/usr/share/freecad/Mod/Fem/femtest/app/test_mesh.py", line 33, in <module>
> 332s     import Fem
> 332s ImportError: libvtkWrappingPythonCore3.13-9.5.so.1: cannot open shared object file: No such file or directory
> 
> One possible easy solution would be to build vtk9 against all supported python3 versions,
> thus during the transition libvtk9 would have both 3.13 and 3.14 builds, and it would
> be dropped once the older version is no longer "supported" (i.e. included in
> python3-all).
> 
> Another option would be to have some dependencies, e.g. through a
> Provides: libvtkwrapping-python3.XX and corresponding deps in rdeps.

The better solution is for dh_python3 to emit dependencies
  python3 (>= 3.14~), python3 (<< 3.15)

I'm merging this with the existing bug for that, there is no point in 
working around this issue in a gazillion packages.

freecad-python3 has the same issue (though it might not be tested by an 
autopkgtest:
 Depends: ..., libpython3.14 (>= 3.14.1),...

Without the autopkgtest blocking due to this issue in vtk9 freecad would 
have already migrated, resulting in freecad-python3 segfaulting in testing.

> Cheers,
> Emilio
>...

cu
Adrian