$ git clone -n https://src.fedoraproject.org/rpms/erlang-stun.git /var/lib/mock/f41-build-side-1-2811277-32927/root/chroot_tmpdir/scmroot/erlang-stun
Cloning into '/var/lib/mock/f41-build-side-1-2811277-32927/root/chroot_tmpdir/scmroot/erlang-stun'...
$ git fetch origin a26e81e100a23377e91a8510841b5716b084c5a3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-stun
 * [new ref]         a26e81e100a23377e91a8510841b5716b084c5a3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a26e81e stun ver. 1.2.14