$ git clone -n https://src.fedoraproject.org/rpms/libxnm.git /var/lib/mock/f41-build-side-1-2647737-27311/root/chroot_tmpdir/scmroot/libxnm
Cloning into '/var/lib/mock/f41-build-side-1-2647737-27311/root/chroot_tmpdir/scmroot/libxnm'...
$ git fetch origin 4f703d34c889531789fc6d6d1f8aa9f37ab3c9a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libxnm
 * [new ref]         4f703d34c889531789fc6d6d1f8aa9f37ab3c9a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4f703d3 convert GPLv2+ license to SPDX