$ git clone -n https://src.fedoraproject.org/rpms/golang-x-sys.git /var/lib/mock/f39-build-2215172-52410/root/chroot_tmpdir/scmroot/golang-x-sys
Cloning into '/var/lib/mock/f39-build-2215172-52410/root/chroot_tmpdir/scmroot/golang-x-sys'...
$ git fetch origin 944d685b355281b5fb7931b5136b684b2e181863:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-x-sys
 * [new ref]         944d685b355281b5fb7931b5136b684b2e181863 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 944d685 update to v0.16.0, close rhbz#2257072