$ git clone -n https://src.fedoraproject.org/rpms/erlang-fast_xml.git /var/lib/mock/f40-build-1931795-25123/root/chroot_tmpdir/scmroot/erlang-fast_xml
Cloning into '/var/lib/mock/f40-build-1931795-25123/root/chroot_tmpdir/scmroot/erlang-fast_xml'...
$ git fetch origin 68c3a588b196278e1e59d303b78664fa6a1f90c0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-fast_xml
 * [new ref]         68c3a588b196278e1e59d303b78664fa6a1f90c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 68c3a58 t_xml ver. 1.1.52