This is a feature request. When a website / ip address is given without a scheme (e.g. http://website), but no scheme is specified, libzilla fails because no scheme was given. The help text says "all communications are carried out using the bugzilla REST API and HTTPS scheme". Therefore, defaulting to https when no scheme is given seems like a sane default.
Thanks for the bug report! Yes, there's definitely something up with the way schemes are handled.
commit 7210e3eb4c81a046ebad4ee3f0cdb03d2c4bb597 (HEAD -> master, origin/master) Author: Patrice Clement <monsieurp@gentoo.org> AuthorDate: Mon Jul 11 16:08:37 2016 +0200 Commit: Patrice Clement <monsieurp@gentoo.org> CommitDate: Mon Jul 11 16:08:37 2016 +0200 Rework scheme resolution. Gentoo-Bug: https://bugs.gentoo.org/588478 libzilla/validator.py | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) Please give it a try!