Use a patch instead of sed

Author: dra27

packages/ocamlfind/ocamlfind.1.9.6/files/0001-Harden-test-for-OCaml-5.patch

@@ -0,0 +1,12 @@
+diff a/configure b/configure
+--- a/configure
++++ b/configure
+@@ -294,7 +294,7 @@
+     # If findlib has been configured -sitelib $(ocamlc -where) then there's
+     # nothing to do, but otherwise we need to put OCaml's Standard Library
+     # into the path setting.
+-    if [ ! -e "${ocaml_sitelib}/stdlib/META" ]; then
++    if [ ! -e "${ocaml_sitelib}/stdlib.cmi" ]; then
+         ocamlpath="${ocaml_core_stdlib}${path_sep}${ocamlpath}"
+     fi
+ fi

packages/ocamlfind/ocamlfind.1.9.6/opam

@@ -17,8 +17,6 @@ depends: [
 ]
 depopts: ["graphics"]
 build: [
-  # See https://github.com/ocaml/ocamlfind/pull/61
-  ["sed" "-ib" "s|stdlib/META|stdlib.cmi|" "configure"]
   [
     "./configure"
     "-bindir" bin
@@ -36,6 +34,9 @@ install: [
   [make "install"]
   ["install" "-m" "0755" "ocaml-stub" "%{bin}%/ocaml"] {ocaml:preinstalled}
 ]
+extra-files: ["0001-Harden-test-for-OCaml-5.patch" "md5=3cddbf72164c29d4e50e077a92a37c6c"]
+# See https://github.com/ocaml/ocamlfind/pull/61
+patches: ["0001-Harden-test-for-OCaml-5.patch"]
 dev-repo: "git+https://github.com/ocaml/ocamlfind.git"
 url {
   src: "http://download.camlcity.org/download/findlib-1.9.6.tar.gz"