$ git clone -n https://src.fedoraproject.org/rpms/NLopt.git /var/lib/mock/f41-build-side-1-2920123-34902/root/chroot_tmpdir/scmroot/NLopt
Cloning into '/var/lib/mock/f41-build-side-1-2920123-34902/root/chroot_tmpdir/scmroot/NLopt'...
$ git fetch origin f56cb68889eb55ee40e16c5dcd0119d1dac836db:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/NLopt
 * [new ref]         f56cb68889eb55ee40e16c5dcd0119d1dac836db -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f56cb68 Update to 2,8.0