From ebf6790c393f4e89eede6d8049c95dc738734bea Mon Sep 17 00:00:00 2001
From: Someone Serge <sergei.kozlukov@aalto.fi>
Date: Thu, 15 Aug 2024 23:37:46 +0000
Subject: [PATCH] stdenv: concatTo: fall back to old behaviour for "*Array"
 variables

Fixes e.g. the `sudo` build failure
---
 pkgs/stdenv/generic/setup.sh | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index ea61ec7509ce..ef645e4e513e 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -400,8 +400,15 @@ concatTo() {
                 -a*)
                     targetref+=( "${nameref[@]}" ) ;;
                 *)
-                    # shellcheck disable=SC2206
-                    targetref+=( ${nameref-} ) ;;
+                    if [[ "$name" = *"Array" ]]; then
+                        nixErrorLog "concatTo(): $name is not declared as array, treating as a singleton. This will become an error in future"
+                        # Reproduces https://github.com/NixOS/nixpkgs/pull/318614/files#diff-7c7ca80928136cfc73a02d5b28350bd900e331d6d304857053ffc9f7beaad576L359
+                        targetref+=( ${nameref+"${nameref[@]}"} )
+                    else
+                        # shellcheck disable=SC2206
+                        targetref+=( ${nameref-} )
+                    fi
+                    ;;
             esac
         fi
     done