Install trexio in OCaml if it is not on the system

ocaml/trexio/compile-lib.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+PREFIX=$1
+PKGCONFIG_COMMAND="pkg-config --libs --cflags trexio"
+
+INSTALLED="no"
+
+# Try with system defaults
+if cc test.c >/dev/null 2>&1 ; then
+  exit
+fi
+
+# Try with pkg-config
+if eval $PKGCONFIG_COMMAND >/dev/null 2>&1; then
+    exit
+fi
+
+# Compile C library
+cd vendor
+tar -zxf trexio-*.tar.gz
+cd trexio-*
+./configure --prefix=${PREFIX}
+$(MAKE) install && \
+rm -rf trexio-*/
+

ocaml/trexio/trexio.opam

@@ -0,0 +1,42 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+version: "2.3.0"
+synopsis: "Binding for the TREXIO Input/Output library"
+description:
+  "TREXIO is a file format and library for storing wave functions and integrals for quantum chemistry."
+maintainer: ["Anthony Scemama <scemama@irsamc.ups-tlse.fr>"]
+authors: [
+  "Anthony Scemama <scemama@irsamc.ups-tlse.fr>"
+  "Evgeny Posenitskiy <posenitskiy@irsamc.ups-tlse.fr>"
+]
+license: "BSD-3-Clause"
+tags: ["Quantum chemistry" "Library"]
+homepage: "https://github.com/trex-coe/trexio_ocaml"
+doc: "https://trex-coe.github.io/trexio/"
+bug-reports: "https://github.com/trex-coe/trexio_ocaml/issues"
+depends: [
+  "dune" {>= "3.1"}
+  "dune-configurator" {build}
+  "conf-pkg-config" {build}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  ["./compile-lib.sh" "%{prefix}%" "build"]
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+install: [
+ ["./compile-lib.sh" "%{prefix}%" "install"]
+ ["dune" "install"]
+]
+dev-repo: "git+https://github.com/trex-coe/trexio_ocaml.git"