$ git clone -n https://src.fedoraproject.org/rpms/rust-utf-8.git /var/lib/mock/f45-build-46037-830/root/chroot_tmpdir/scmroot/rust-utf-8
Cloning into '/var/lib/mock/f45-build-46037-830/root/chroot_tmpdir/scmroot/rust-utf-8'...
$ git fetch origin 68be31b9a028b43400b07e9e320e676bc5ab8510:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-utf-8
 * [new ref]         68be31b9a028b43400b07e9e320e676bc5ab8510 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 68be31b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild