$ git clone -n https://src.fedoraproject.org/rpms/python3.9.git /var/lib/mock/f39-build-1619732-38674/root/chroot_tmpdir/scmroot/python3.9
Cloning into '/var/lib/mock/f39-build-1619732-38674/root/chroot_tmpdir/scmroot/python3.9'...
$ git fetch origin 77e0d4f1565ada8d2387b873afe56a62d71d4e1d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python3.9
 * [new ref]         77e0d4f1565ada8d2387b873afe56a62d71d4e1d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77e0d4f Update to 3.9.18