akstrfn [1] filed a deletion request for qcustomplot-qt5 [2]: David Runge added qcustomplot package to community so there is no need for this aur package.
Its not nice that he didn't give any notification about this and I found out when I updated my system... [1] https://aur.archlinux.org/account/akstrfn/ [2] https://aur.archlinux.org/pkgbase/qcustomplot-qt5/
