$ git clone -n https://src.fedoraproject.org/rpms/cockpit-composer.git /var/lib/mock/f39-build-1531158-36207/root/chroot_tmpdir/scmroot/cockpit-composer
Cloning into '/var/lib/mock/f39-build-1531158-36207/root/chroot_tmpdir/scmroot/cockpit-composer'...
$ git fetch origin d6441b509b69bcbafd714e9a42a36e9cd37aefa3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cockpit-composer
 * [new ref]         d6441b509b69bcbafd714e9a42a36e9cd37aefa3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d6441b5 [packit] 47 upstream release