$ git clone -n https://src.fedoraproject.org/rpms/fedora-messaging.git /var/lib/mock/f45-build-8861-396/root/chroot_tmpdir/scmroot/fedora-messaging
Cloning into '/var/lib/mock/f45-build-8861-396/root/chroot_tmpdir/scmroot/fedora-messaging'...
$ git fetch origin b61d039d7b70b9b67391ad3c590f9cc28905757b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fedora-messaging
 * [new ref]         b61d039d7b70b9b67391ad3c590f9cc28905757b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b61d039 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild