$ git clone -n https://src.fedoraproject.org/rpms/erlang-hex_core.git /var/lib/mock/f45-build-8335-384/root/chroot_tmpdir/scmroot/erlang-hex_core
Cloning into '/var/lib/mock/f45-build-8335-384/root/chroot_tmpdir/scmroot/erlang-hex_core'...
$ git fetch origin 6ff82e317bcd534a033ceaf190234a650d7216af:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-hex_core
 * [new ref]         6ff82e317bcd534a033ceaf190234a650d7216af -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6ff82e3 hex_core ver. 0.19.0