Turns out it was not even just a patch file that was hosted on the dead server, but the whole, compiled postgresql package in a binary RPM file. Anyway, one more reason to delete this suspicious package. On 5 July 2023 00:28:00 GMT+02:00, notify@aur.archlinux.org wrote:

MarsSeed [1] filed a deletion request for postgresql-1c [2]:

Orphan duplicate postgresql package with an unspecified patch hosted on r-s-v.ru which is defunct, so the patch source is 404.

[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/postgresql-1c/