From c9fe9f306534386ceb15b8cd5572b9e6013f57a0 Mon Sep 17 00:00:00 2001
From: Kate <kit-ty-kate@outlook.com>
Date: Thu, 6 Jun 2024 09:54:59 +0100
Subject: [PATCH] Display lock hold/release messages on stderr instead of
 stdout

---
 master_changes.md        |  2 ++
 src/core/opamConsole.ml  | 12 +++++++-----
 src/core/opamConsole.mli |  1 +
 src/core/opamSystem.ml   |  6 +++---
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/master_changes.md b/master_changes.md
index 8f559742d8a..702f6274bfb 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -18,6 +18,7 @@ users)
 ## Global CLI
   * Fix a typo in the variable description returned by "opam var" [#5961 @jmid]
   * Out-of-the-box UTF-8 paged --help on Windows [#5970 @kit-ty-kate]
+  * ✘ Display lock hold/release messages on stderr instead of stdout [#5999 @kit-ty-kate - fix #5990]
 
 ## Plugins
 
@@ -176,3 +177,4 @@ users)
   * `OpamStubs.getVersionInfo`: on Windows, retrives the version information block of an executable/library [#5963 @dra27]
   * `OpamStubs.readRegistry`: on Windows, complements `OpamStubs.writeRegistry` [#5963 @dra27]
   * `OpamStubs.get_initial_environment`: on Windows, returns the pristine environment for new shells [#5963 @dra27]
+  * `OpamConsole`: Add `formatted_errmsg` [#5999 @kit-ty-kate]
diff --git a/src/core/opamConsole.ml b/src/core/opamConsole.ml
index 2e993f3d8c6..bfc434c6df0 100644
--- a/src/core/opamConsole.ml
+++ b/src/core/opamConsole.ml
@@ -610,7 +610,13 @@ let note fmt =
       (OpamStd.Format.reformat ~start_column:7 ~indent:7 str)
   ) fmt
 
+let formatted_msg_aux ~indent out fmt =
+  Printf.ksprintf
+    (fun s -> print_message out "%s" (OpamStd.Format.reformat ?indent s))
+    fmt
+
 let errmsg fmt = print_message `stderr fmt
+let formatted_errmsg ?indent fmt = formatted_msg_aux ~indent `stderr fmt
 
 let error_and_exit reason fmt =
   Printf.ksprintf (fun str ->
@@ -619,11 +625,7 @@ let error_and_exit reason fmt =
   ) fmt
 
 let msg fmt = print_message `stdout fmt
-
-let formatted_msg ?indent fmt =
-  Printf.ksprintf
-    (fun s -> print_message `stdout "%s" (OpamStd.Format.reformat ?indent s))
-    fmt
+let formatted_msg ?indent fmt = formatted_msg_aux ~indent `stdout fmt
 
 let last_status = ref ""
 
diff --git a/src/core/opamConsole.mli b/src/core/opamConsole.mli
index c82fae1bbf4..5244b4a00f2 100644
--- a/src/core/opamConsole.mli
+++ b/src/core/opamConsole.mli
@@ -93,6 +93,7 @@ val note : ('a, unit, string, unit) format4 -> 'a
 (** Message without prefix, reformat or newline, to stderr (useful to continue
     error messages without repeating "[ERROR]") *)
 val errmsg : ('a, unit, string, unit) format4 -> 'a
+val formatted_errmsg : ?indent:int -> ('a, unit, string, unit) format4 -> 'a
 
 val error_and_exit :
   OpamStd.Sys.exit_reason -> ('a, unit, string, 'b) format4 -> 'a
diff --git a/src/core/opamSystem.ml b/src/core/opamSystem.ml
index 1282e307094..925a232469a 100644
--- a/src/core/opamSystem.ml
+++ b/src/core/opamSystem.ml
@@ -1224,15 +1224,15 @@ let rec flock_update
            OpamConsole.error_and_exit `Locked
              "Another process has locked %s and non blocking mode enabled"
              file;
-         OpamConsole.formatted_msg
+         OpamConsole.formatted_errmsg
            "Another process has locked %s, waiting (%s to abort)... "
            file (if Sys.win32 then "CTRL+C" else "C-c");
          let rec lock_w_ignore_sig () =
            try Unix.lockf fd (unix_lock_op ~dontblock:false flag) 0;
-           with Sys.Break as e -> (OpamConsole.msg "\n"; raise e)
+           with Sys.Break as e -> (OpamConsole.errmsg "\n"; raise e)
               | Unix.Unix_error (Unix.EINTR,_,_) -> lock_w_ignore_sig ()
          in lock_w_ignore_sig ();
-         OpamConsole.msg "lock acquired.\n");
+         OpamConsole.errmsg "lock acquired.\n");
     lock.kind <- (flag :> lock_flag)
   | _ -> assert false