$ git clone -n https://src.fedoraproject.org/rpms/nats-server.git /var/lib/mock/f40-build-2105029-50574/root/chroot_tmpdir/scmroot/nats-server
Cloning into '/var/lib/mock/f40-build-2105029-50574/root/chroot_tmpdir/scmroot/nats-server'...
$ git fetch origin f91647048bb3cfa56446ce2528f20a55e76e5535:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nats-server
 * [new ref]         f91647048bb3cfa56446ce2528f20a55e76e5535 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f916470 update to v2.10.7, close rhbz#2253525