$ git clone -n https://src.fedoraproject.org/rpms/rust-rusttype.git /var/lib/mock/f39-build-1544051-36610/root/chroot_tmpdir/scmroot/rust-rusttype
Cloning into '/var/lib/mock/f39-build-1544051-36610/root/chroot_tmpdir/scmroot/rust-rusttype'...
$ git fetch origin b3fec3bc747d2075614038c919712b73157a6865:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rusttype
 * [new ref]         b3fec3bc747d2075614038c919712b73157a6865 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b3fec3b Update to 0.9.3; Fixes: RHBZ#2224848