$ git clone -n https://src.fedoraproject.org/rpms/libidn.git /var/lib/mock/f40-build-2237820-53551/root/chroot_tmpdir/scmroot/libidn
Cloning into '/var/lib/mock/f40-build-2237820-53551/root/chroot_tmpdir/scmroot/libidn'...
$ git fetch origin 8ef168001604f1ca2042077db913a96ef81e17c0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libidn
 * [new ref]         8ef168001604f1ca2042077db913a96ef81e17c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8ef1680 convert license tag to SPDX