this is very, very strange.
I have the following in my /etc/pacman.conf
[core]
SigLevel = PackageRequired
Include = /etc/pacman.d/mirrorlist
[extra]
SigLevel = PackageRequired
Include = /etc/pacman.d/mirrorlist
[multilib]
SigLevel = PackageRequired
Include = /etc/pacman.d/mirrorlist
Does yours look like that?
and for mirror list, I have the following mirrors:
Server = https://mirror.stephanie.is/archlinux/$repo/os/$arch
Server = https://nocix.mm.fcix.net/archlinux/$repo/os/$arch
Server = https://ohioix.mm.fcix.net/archlinux/$repo/os/$arch
Server = https://mnvoip.mm.fcix.net/archlinux/$repo/os/$arch
Server = https://arch.mirror.ivo.st/$repo/os/$arch
these settings yield me the python library just fine
My only gut ‘guess’ is that your original mirror was out of date, then you happened to switch to one mid sync potentially.