$ git clone -n https://src.fedoraproject.org/rpms/perl-VM-EC2.git /var/lib/mock/f45-build-27380-622/root/chroot_tmpdir/scmroot/perl-VM-EC2
Cloning into '/var/lib/mock/f45-build-27380-622/root/chroot_tmpdir/scmroot/perl-VM-EC2'...
$ git fetch origin b56773e9f150f49d905db888916f323f5bf6b76c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-VM-EC2
 * [new ref]         b56773e9f150f49d905db888916f323f5bf6b76c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b56773e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild