$ git clone -n https://src.fedoraproject.org/rpms/golang-github-nxadm-tail.git /var/lib/mock/f42-build-867305-175384/root/chroot_tmpdir/scmroot/golang-github-nxadm-tail
Cloning into '/var/lib/mock/f42-build-867305-175384/root/chroot_tmpdir/scmroot/golang-github-nxadm-tail'...
$ git fetch origin 8eec13ec3396e1389e85345f3af979dcec41473e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-nxadm-tail
 * [new ref]         8eec13ec3396e1389e85345f3af979dcec41473e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8eec13e Fix FTBFS - Closes rhbz#2300763