$ git clone -n https://src.fedoraproject.org/rpms/postgrey.git /var/lib/mock/f45-build-28846-633/root/chroot_tmpdir/scmroot/postgrey
Cloning into '/var/lib/mock/f45-build-28846-633/root/chroot_tmpdir/scmroot/postgrey'...
$ git fetch origin 9ad6e647725dd5a463c3a28384837df582c74f77:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/postgrey
 * [new ref]         9ad6e647725dd5a463c3a28384837df582c74f77 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9ad6e64 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild