k0ste [1] filed a deletion request for oauth2-proxy [2]: Duplicate https://aur.archlinux.org/packages/oauth2_proxy The old version is better, at least it have a dedicated user (but still lack of sysusers support)
[1] https://aur.archlinux.org/account/k0ste/ [2] https://aur.archlinux.org/pkgbase/oauth2-proxy/
