$ git clone -n https://src.fedoraproject.org/rpms/ntl.git /var/lib/mock/f39-build-1963260-43277/root/chroot_tmpdir/scmroot/ntl
Cloning into '/var/lib/mock/f39-build-1963260-43277/root/chroot_tmpdir/scmroot/ntl'...
$ git fetch origin 8ac1236e5120550d5c619a391afeae18e3a7b2a7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ntl
 * [new ref]         8ac1236e5120550d5c619a391afeae18e3a7b2a7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8ac1236 Use a more reliable way of detecting CPU features