[Debian-med-packaging] Bug#808505: invesalius: Uninstallable due to conflicting dependencies (python-vtk vs python-vtk6)

[Axel Beckert]

Package: invesalius
Severity: serious

Hi,

invesalius has become uninstallable since one of transitions a few weeks
ago (maybe the GSL-2.0 transition). Trying to install it in a clean Sid
chroot ends as follows:

root at c-cactus2:/# apt-get install invesalius
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 invesalius : Depends: python-casmoothing but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
root at c-cactus2:/# 

The core of the issue seems to be that it depends on both, python-vtk6
and python-vtk which are not co-installable as python-vtk6 conflicts
with python-vtk.

python-vtk is a direct dependency of invesalius while the direct
dependency python-casmoothing depends on python-vtk6 nowadays.

This piuparts test failure also shows this issue:
https://piuparts.debian.org/sid/fail/invesalius_3.0-1.log

I assume that switching all of invesalius to vtk6 might solve this
issue. I just have no idea how easy or difficult this will be.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (600, 'testing'), (111, 'buildd-unstable'), (111, 'buildd-experimental'), (110, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.3.0-trunk-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)