From 4b1c49fedec451dd9d94f3692191e5df45147a84 Mon Sep 17 00:00:00 2001
From: Lin Jian <me@linj.tech>
Date: Wed, 5 Mar 2025 10:08:16 +0800
Subject: [PATCH] emacs.pkgs.irony: respect old.env in overrideAttrs

---
 .../editors/emacs/elisp-packages/melpa-packages.nix             | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
index 2ed31090e106..1108d0e154b6 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
@@ -294,7 +294,7 @@ let
 
         irony = super.irony.overrideAttrs (old: {
           cmakeFlags = old.cmakeFlags or [ ] ++ [ "-DCMAKE_INSTALL_BINDIR=bin" ];
-          env.NIX_CFLAGS_COMPILE = "-UCLANG_RESOURCE_DIR";
+          env = old.env or { } // { NIX_CFLAGS_COMPILE = "-UCLANG_RESOURCE_DIR"; };
           preConfigure = ''
             pushd server
           '';