MarsSeed [1] filed a deletion request for qtcreator-markview-plugin- git [2]:
Broken, discontinued Qt Creator 5.x plugin from 3 years ago. [a] Not compatible with current qtcreator (12+). [a]: https://github.com/OneMoreGres/qtc-markview [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/qtcreator-markview-plugin-git/