gnu: Add ocaml-async.

* gnu/packages/ocaml.scm (ocaml-async): New variable.

Signed-off-by: Christopher Baines <mail@cbaines.net>

gnu/packages/ocaml.scm

@@ -8490,6 +8490,41 @@ (define-public ocaml-async-rpc-kernel
 JavaScript.")
     (license license:expat)))
 
+(define-public ocaml-async
+  (package
+    (name "ocaml-async")
+    (version "0.15.0")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/janestreet/async")
+                    (commit (string-append "v" version))))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32
+                "0pykmnsil754jsnr8gss91ykyjvivngx4ii0ih3nsg1x2jl9xmy2"))))
+    (build-system dune-build-system)
+    (propagated-inputs (list ocaml-async-kernel
+                             ocaml-async-rpc-kernel
+                             ocaml-async-unix
+                             ocaml-core
+                             ocaml-core-kernel
+                             ocaml-core-unix
+                             ocaml-ppx-jane
+                             ocaml-ppx-log
+                             ocaml-textutils))
+    ;; TODO one test dependency is deprecated, the other is nowhere to be found
+    (arguments
+     '(#:tests? #f))
+    ;; (native-inputs (list ocaml-netkit-sockets ocaml-qtest-deprecated))
+    (home-page "https://github.com/janestreet/async")
+    (synopsis "Asynchronous execution library")
+    (description
+     "Library for asynchronous programming, i.e., programming where some part
+of the program must wait for things that happen at times determined by some
+external entity (like a human or another program).")
+    (license license:expat)))
+
 (define-public ocaml-textutils-kernel
   (package
     (name "ocaml-textutils-kernel")