From 45c3600bb13554ab0c68a6a3d2d3d5fe0af39ef3 Mon Sep 17 00:00:00 2001
From: Antonio Nuno Monteiro <anmonteiro@gmail.com>
Date: Fri, 10 Mar 2023 19:08:39 -0800
Subject: [PATCH] buildDunePackage: fix doc installation

The default directory where dune expects docs is in
`$out/doc`, but Nix installs it in `$out/share/doc`
---
 pkgs/build-support/ocaml/dune.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkgs/build-support/ocaml/dune.nix b/pkgs/build-support/ocaml/dune.nix
index ce3b389b9cee..1ad2d236446a 100644
--- a/pkgs/build-support/ocaml/dune.nix
+++ b/pkgs/build-support/ocaml/dune.nix
@@ -30,7 +30,10 @@ stdenv.mkDerivation ({
   '';
   installPhase = ''
     runHook preInstall
-    dune install --prefix $out --libdir $OCAMLFIND_DESTDIR ${pname}
+    dune install --prefix $out --libdir $OCAMLFIND_DESTDIR ${pname} \
+     ${if lib.versionAtLeast Dune.version "2.9"
+       then "--docdir $out/share/doc"
+       else ""}
     runHook postInstall
   '';