virtmanager: Namespace LibvirtGLib not available

[lschuermann]

Issue description

I just did a fresh installation of NixOS and I am on the unstable channel. When starting virt-manager I'm getting the following error message:

[nix-shell:~]$ virt-manager 
Traceback (most recent call last):
  File "/nix/store/f0qsv1lmwdfzlbahsscqnqdilriz5xlg-virt-manager-1.4.3/share/virt-manager/virt-manager", line 32, in <module>
    gi.require_version('LibvirtGLib', '1.0')
  File "/nix/store/p6fnhmmvr28ziv19c37hr9n6vkcy25an-python2.7-pygobject-3.26.1/lib/python2.7/site-packages/gi/__init__.py", line 130, in require_version
    raise ValueError('Namespace %s not available' % namespace)
ValueError: Namespace LibvirtGLib not available

This happens when installed as a system-package, in the user environment and in the nix shell.

The package works as expected in a nix-shell based on the 17.09 release:
nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-17.09.tar.gz -p virtmanager

Steps to reproduce

Install pkgs.virtmanager on a NixOS system with the unstable channel selected.

Technical details

• system: "x86_64-linux"
• host os: Linux 4.9.75, NixOS, 18.03pre125026.f607771d0f5 (Impala)
• multi-user?: yes
• sandbox: no
• version: nix-env (Nix) 1.12pre5810_5d5b931f
• channels(root): "nixos"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[jtojnar]

See #33754

[lschuermann]

Oh, okay, must have missed that PR. I'll guess we'll just use the old release's version until the fix reached the unstable channel.