Support OCaml 5 new Unix primitive names

Author: dra27

src/unix/dune

@@ -8,6 +8,13 @@ let preprocess =
 
 let () = Jbuild_plugin.V1.send @@ {|
 
+(rule
+ (targets lwt_process.ml)
+ (deps (:ml lwt_process.cppo.ml))
+ (action
+  (chdir %{project_root}
+   (run %{bin:cppo} -V OCAML:%{ocaml_version} %{ml} -o %{targets}))))
+
 (rule
  (targets lwt_unix.ml)
  (deps (:ml lwt_unix.cppo.ml))

src/unix/lwt_process.ml src/unix/lwt_process.cppo.mlsrc/unix/lwt_process.ml renamed to src/unix/lwt_process.cppo.ml

@@ -136,7 +136,11 @@ let unix_redirect fd redirection = match redirection with
     Unix.dup2 fd' fd;
     Unix.close fd'
 
+#if OCAML_VERSION >= (5, 0, 0)
+external unix_exit : int -> 'a = "caml_unix_exit"
+#else
 external unix_exit : int -> 'a = "unix_exit"
+#endif
 
 let unix_spawn
     ?cwd

src/unix/lwt_unix.cppo.ml

@@ -2434,7 +2434,11 @@ let wait () = waitpid [] (-1)
 
 external system_job : string -> int job = "lwt_unix_system_job"
 
+#if OCAML_VERSION >= (5, 0, 0)
+external unix_exit : int -> 'a = "caml_unix_exit"
+#else
 external unix_exit : int -> 'a = "unix_exit"
+#endif
 
 let system cmd =
   if Sys.win32 then