Expected Behavior

"abc" is printed at the step 5 in the reproduce steps below.

Actual Behavior

Nothing is printed at the step 5 in the reproduce steps below.

Reproduction

1. Create a new project directory for reproduce: dune init dune-repro
2. Enter the project directory: cd dune-repro
3. Change bin/main.ml to this:

   let () = print_endline @@ read_line ()

4. dune exec dune-repro
5. Type abc<Enter> (where the <Enter> means the enter key)

Specifications

• Version of dune (output of dune --version): 3.19.0
• Version of ocaml (output of ocamlc --version): 5.3.0
• Operating system (distribution and version): macOS 15.4.1
• Shell: bash 5.2.37

  GNU bash, version 5.2.37(1)-release (aarch64-apple-darwin23.4.0)
  Copyright (C) 2022 Free Software Foundation, Inc.
  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
  
  This is free software; you are free to change and redistribute it.
  There is NO WARRANTY, to the extent permitted by law.
  

Additional information

• If you run the binary directly from the shell, this bug does not happen: ./_build/install/default/bin/dune-repro
• This bug is not reproducible with dune 3.18.2.
  • When I tried this, I modified the dune-project file in order to run this project with older dune:

    diff --git a/dune-project b/dune-project
    index 7caa58a..a2241c1 100644
    --- a/dune-project
    +++ b/dune-project
    @@ -1,4 +1,4 @@
    -(lang dune 3.19)
    +(lang dune 3.18)
    
     (name dune-repro)

• As far as I bisected, this bug is introduced in this commit: 6fa1f6e