$ git clone -n https://src.fedoraproject.org/rpms/pacman.git /var/lib/mock/f45-build-21318-583/root/chroot_tmpdir/scmroot/pacman
Cloning into '/var/lib/mock/f45-build-21318-583/root/chroot_tmpdir/scmroot/pacman'...
$ git fetch origin 4fdd78ccf80cbb727b127c614c757e5353bec630:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pacman
 * [new ref]         4fdd78ccf80cbb727b127c614c757e5353bec630 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4fdd78c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild