New comment by teldra on void-packages repository

https://github.com/void-linux/void-packages/pull/28806#issuecomment-780613503

Comment:
> This looks like it's looking for X server. Maybe use `xvfb-run dbus-run-session`?

Yes that did the Trick.

Now the funny parts: 
- No tests were executed. Should I instead add `do_check() { : }`? https://github.com/void-linux/void-packages/pull/28806/checks?check_run_id=1919520285#step:8:108
- Right now, I had to add `post_extract()`. Without it, this happens:
```
/builddir/volctl-0.8.2/volctl/meta.py:2: PyGIWarning: Gtk was imported without specifying a version first. Use gi.require_version('Gtk', '3.0') before import to ensure that the right version gets loaded.
  from gi.repository import Gtk
```