MarsSeed [1] filed a deletion request for qbzr [2]: Orphaned package, last updated 6 years ago.
Legacy Python 2 and Qt4 based frontend for Canonical's Bazaar (bzr), a Python 2 based VCS CLI client discontinued in 2017. This frontend doesn't work with the Python 3 based continuation fork, breezy (carried by Arch repos). So I recommend deleting it. There is at least one alternative GUI for Breezy in Arch repos: zim. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/qbzr/
