It doesn't even look like a legitimate package, all it does is fetch a script and run it.

On Sat, Feb 6, 2021 at 4:47 PM notify--- via aur-requests <aur-requests@lists.archlinux.org> wrote:

hwittenborn [1] filed a deletion request for checkra1n-cn [2]:

Seems to try to look like the official package(checkra.in), but
doesn't include the URL for it in the PKGBUILD(or scripts contained
within it).

[1] https://aur.archlinux.org/account/hwittenborn/
[2] https://aur.archlinux.org/pkgbase/checkra1n-cn/