'openvr' is an optional dependency (so is python) - that normally
suggests a package which is mostly useful without any optional
dependencies; but has some extra functionality when some/any
optional dependencies are present

if that describes the relationship between 'vtk' and 'openvr',
the depends/optdepends are probably correct now (understood
semantically, and expected by savvy users of an arch system)

that python error makes it appear that there is an intrinsic
dependency; but it may not be so, or it may be so only for
python programs

it appears that all related packages ('vtk', 'openvr', and
'python') come directly from arch; so the first thing to do
is to see if arch's python behaves the same, and/or if a
bug report exists already about it

it looks like this is a known issue in arch https://bugs.archlinux.org/task/61655

that BR suggests, contrary to the normal general cases i described before, that 'vtk', especially when used via python, will fail if any libs are missing, which the vtk lib was compiled to support

this is what i get on arch:

$ python -c 'import vtk'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3.10/site-packages/vtk.py", line 31, in <module>
    all_m = importlib.import_module('vtkmodules.all')
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/lib/python3.10/site-packages/vtkmodules/all.py", line 8, in <module>
    from .vtkWebCore import *
ImportError: libpugixml.so.1: cannot open shared object file: No such file or directory

this is what i get on parabola:

$ python -c 'import vtk'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3.10/site-packages/vtk.py", line 31, in <module>
    all_m = importlib.import_module('vtkmodules.all')
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/lib/python3.10/site-packages/vtkmodules/all.py", line 8, in <module>
    from .vtkWebCore import *
ImportError: libfmt.so.8: cannot open shared object file: No such file or directory

the exact error depends on which of vtk's true dependencies are and are not installed -
i had 'pugixml' installed already - after installing 'fmt':

$ python -c 'import vtk'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3.10/site-packages/vtk.py", line 31, in <module>
    all_m = importlib.import_module('vtkmodules.all')
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/lib/python3.10/site-packages/vtkmodules/all.py", line 46, in <module>
    from .vtkRenderingRayTracing import *
ImportError: libospray.so.2: cannot open shared object file: No such file or directory

'openvr', 'ospray', and 'pugixml' are all in optdepends - 'fmt' is not - ive a feeling this is a deep rabbit-hole

Plop! (comical fall).

Should we then mark this as "forwarded upstream" or "confirmed"?

as an update, the arch packager believes that since v9 of vtk, it is recommended for any script not to import the entire 'vtk' module - seems like a poor design to me (why not simply make them separate modules, and avoid the confusion with a technical solution); but my mind is admittedly not very "pythonical"

Hi. I think I got a reincarnation of this with a package from the AUR that tries to use VTK (without importing the full vtk):

import pyvista

  File "/usr/lib/python3.11/site-packages/pyvista/__init__.py", line 9, in <module>
    from pyvista.core import *
  File "/usr/lib/python3.11/site-packages/pyvista/core/__init__.py", line 4, in <module>
    from . import _vtk_core
  File "/usr/lib/python3.11/site-packages/pyvista/core/_vtk_core.py", line 249, in <module>
    from vtkmodules.vtkFiltersExtraction import (
ImportError: libfmt.so.10: cannot open shared object file: No such file or directory

# pacman -S --asdep fmt

import pyvista

Traceback (most recent call last):
  File "<string>", line 17, in __PYTHON_EL_eval
  File "/home/edgar/GlassFibre/Code/examples/dolfinx_cyclic_softening.py", line 29, in <module>
    import pyvista as pv
  File "/usr/lib/python3.11/site-packages/pyvista/__init__.py", line 9, in <module>
    from pyvista.core import *
  File "/usr/lib/python3.11/site-packages/pyvista/core/__init__.py", line 4, in <module>
    from . import _vtk_core
  File "/usr/lib/python3.11/site-packages/pyvista/core/_vtk_core.py", line 249, in <module>
    from vtkmodules.vtkFiltersExtraction import (
ImportError: libverdict.so.1.4: cannot open shared object file: No such file or directory

# pacman -S --asdep verdict

import pyvista

(success)

>>> import pyvista
>>> 

I will try to report it as a bug upstream