It seems this was used as a dependency for feeluown between 2018 and 2019, but not after that.
It is useless on its own.

On 22 June 2022 15:30:40 GMT+02:00, notify@aur.archlinux.org wrote:
MarsSeed [1] filed a deletion request for python-fuocore [2]:

Deprecated since 2019, GitHub repo inactivated;
doesn't support Python 3.8+.
Nothing depends on it, safe to delete.

[1] https://aur.archlinux.org/account/MarsSeed/
[2] https://aur.archlinux.org/pkgbase/python-fuocore/