$ git clone -n https://src.fedoraproject.org/rpms/rust-maxminddb.git /var/lib/mock/f45-build-43151-800/root/chroot_tmpdir/scmroot/rust-maxminddb
Cloning into '/var/lib/mock/f45-build-43151-800/root/chroot_tmpdir/scmroot/rust-maxminddb'...
$ git fetch origin b2e57d28009ea7c7105b00fe8f17baa58747e1c2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-maxminddb
 * [new ref]         b2e57d28009ea7c7105b00fe8f17baa58747e1c2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2e57d2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild