$ git clone -n https://src.fedoraproject.org/rpms/ghc-snap-server.git /var/lib/mock/f45-build-10770-424/root/chroot_tmpdir/scmroot/ghc-snap-server
Cloning into '/var/lib/mock/f45-build-10770-424/root/chroot_tmpdir/scmroot/ghc-snap-server'...
$ git fetch origin 4c83f722ace5c88ec5a994edf4f39ef3eb4645a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-snap-server
 * [new ref]         4c83f722ace5c88ec5a994edf4f39ef3eb4645a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c83f72 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild