17987-herbelin-master+fix17963-search-anomaly-with-evars.sh

overlay coq_dpdgraph https://github.com/herbelin/coq-dpdgraph coq-master+adapt-coq-pr17987-search-pass-sigma 17987
overlay coqhammer https://github.com/herbelin/coqhammer master+adapt-coq-pr17987-search-pass-sigma 17987
overlay serapi https://github.com/herbelin/coq-serapi main+adapt-coq-pr17987-search-pass-sigma 17987
overlay vscoq https://github.com/herbelin/vscoq coq-master+adapt-coq-pr17987-search-pass-sigma 17987