j0hannes [1] filed a deletion request for docear [2]:

upstream project has been abandoned

"Update 2017-08-24: Please note that for the foreseeable future we will not continue the development of Docear as we have not enough funding and time." (https://www.scss.tcd.ie/joeran.beel/blog/2017/02/05/docears-online- services-are-down-recommendation-user-registration-backup/)

[1] https://aur.archlinux.org/account/j0hannes/ [2] https://aur.archlinux.org/pkgbase/docear/