From a242084cde9eaf4ab25b205b71c244c23279704f Mon Sep 17 00:00:00 2001
From: Erik Martin-Dorel <erik.martin-dorel@irit.fr>
Date: Fri, 9 Feb 2024 13:15:16 +0100
Subject: [PATCH] fix: Avoid using `lsof -Q` which is only available from lsof
 4.95.0

(Debian 11 (oldstable) and Ubuntu 22.04 LTS both have lsof 4.93.2.)

The only drawback we could expect is generating a nonzero exit code,
but the current implementation with Unix.open_process_in works as is.
---
 src/server/learnocaml_server.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/server/learnocaml_server.ml b/src/server/learnocaml_server.ml
index 1a4c7664f..f6a61e5b3 100644
--- a/src/server/learnocaml_server.ml
+++ b/src/server/learnocaml_server.ml
@@ -718,7 +718,7 @@ let launch () =
 
 let check_running () =
   try
-    let ic = Printf.ksprintf Unix.open_process_in "lsof -Qti tcp:%d -s tcp:LISTEN" !port in
+    let ic = Printf.ksprintf Unix.open_process_in "lsof -ti tcp:%d -s tcp:LISTEN" !port in
     let pid = match input_line ic with
       | "" -> None
       | s -> int_of_string_opt s