=== modified file 'Makefile'
--- Makefile	2019-04-12 00:15:26 +0000
+++ Makefile	2019-04-11 18:49:43 +0000
@@ -3,7 +3,7 @@
 clean:
 	rm -rf _build *.o *.bc *.cm[iox]
 
-ppio.bc: subprocess.cmo ppio.cmo compile
+ppio.bc: subprocess.cmx ppio.cmx compile
 	./compile subprocess.cmo ppio.cmo -o ppio.bc
 
 %.cmx: %.ml compile

=== modified file 'compile'
--- compile	2019-04-12 00:15:26 +0000
+++ compile	2019-04-11 18:49:43 +0000
@@ -2,7 +2,6 @@
 set -x
 exec ocamlfind ocamlc \
 	-linkpkg \
-	-package async \
 	-package async_unix \
 	-package core \
 	-package base \

=== modified file 'ppio.ml'
--- ppio.ml	2019-04-12 00:15:26 +0000
+++ ppio.ml	2019-04-11 19:04:04 +0000
@@ -57,38 +57,6 @@
   Out_channel.flush stderr;
 ;;
 
-(* Copy data from the reader to the writer, using the provided buffer
-   as scratch space *)
-let rec copy_blocks buffer r w cb =
-  let open Async in
-  Reader.read r buffer
-  >>= function
-  | `Eof ->
-      cb 0 buffer;
-      Reader.close r
-  | `Ok bytes_read ->
-      cb bytes_read buffer;
-      Writer.write w (Bytes.to_string buffer) ~len:bytes_read;
-      Writer.flushed w
-      >>= fun () ->
-      copy_blocks buffer r w cb
-;;
-
-let copy_cb info fd_in fd_out cb = 
-  (* let buffer = Bytes.to_string (Bytes.create (16 * 1024)) in *)
-  let buffer = Bytes.create (16 * 1024) in
-  let create file_descr kind =
-    Async.Unix.Fd.create Fifo file_descr (Info.tag info ~tag:kind)
-  in
-  copy_blocks
-    buffer
-    (Async.Reader.create (create fd_in "reader"))
-    (Async.Writer.create (create fd_out "writer"))
-    cb
-;;
-
-let cb_null (len:int) (buf:Bytes.t) = ();;
-
 let main {hideendl; endl; color; exe} =
   pe ((show_cmd_args {hideendl; endl; color; exe})^"\n");
   let fd0 = Unix.File_descr.of_int 0 in
@@ -111,14 +79,8 @@
     (List.nth_exn exe 0) (List.to_array exe)
   in
   printf "pid: %d\n%!" pid;
-  let open Async in
-  Deferred.all_unit [
-    copy_cb (Info.of_string "stdin") fd0 stdin_w cb_null;
-    copy_cb (Info.of_string "stdout") stdout_r fd1 cb_null;
-  ] >>= (fun () ->
-    let _, status = Subprocess.waitpid [] pid in
-    exit (Subprocess.wait_estatus status);
-  )
+  let _, status = Subprocess.waitpid [] pid in
+  exit (Subprocess.wait_estatus status);
 ;;
 
 let cmd =
@@ -128,7 +90,7 @@
         | true -> Some value
         | false -> None)
   in
-  Async.Command.async ~summary:"Pretty print I/O to a spawned command."
+  Command.basic ~summary:"Pretty print I/O to a spawned command."
   [%map_open
     let hide = flag "-H" ~aliases:["--hide-newlines"] no_arg
       ~doc:"Suppress printing codes of the line-terminating sequence"