$ git clone -n https://src.fedoraproject.org/rpms/ghc-utf8-string.git /var/lib/mock/f45-build-10941-425/root/chroot_tmpdir/scmroot/ghc-utf8-string
Cloning into '/var/lib/mock/f45-build-10941-425/root/chroot_tmpdir/scmroot/ghc-utf8-string'...
$ git fetch origin 5369708a78b8db13e354994ac721e503e48edeb4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-utf8-string
 * [new ref]         5369708a78b8db13e354994ac721e503e48edeb4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5369708 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild