$ git clone -n https://src.fedoraproject.org/rpms/frr.git /var/lib/mock/f39-build-2205792-52030/root/chroot_tmpdir/scmroot/frr
Cloning into '/var/lib/mock/f39-build-2205792-52030/root/chroot_tmpdir/scmroot/frr'...
$ git fetch origin b4aded3d8e0e8e90c5223110b3be98dfe714582d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/frr
 * [new ref]         b4aded3d8e0e8e90c5223110b3be98dfe714582d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4aded3 New version 8.5.4