$ git clone -n https://src.fedoraproject.org/rpms/ghc-dns.git /var/lib/mock/f45-build-10227-414/root/chroot_tmpdir/scmroot/ghc-dns
Cloning into '/var/lib/mock/f45-build-10227-414/root/chroot_tmpdir/scmroot/ghc-dns'...
$ git fetch origin b4f562eda98ce531dab4bfe09f05dfbfda701251:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-dns
 * [new ref]         b4f562eda98ce531dab4bfe09f05dfbfda701251 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4f562e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild