MarsSeed [1] filed a deletion request for jupyter_contrib_core [2]: This package is useless on its own.
It is a module of AUR/jupyter_contrib_nbextensions, which is EOL/unmaintained, and not compatible with the majorly overhauled API of jupyter-notebook v7.x that is in Arch extra repo. See deletion request PRQ#67078 for that AUR package. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/jupyter_contrib_core/
