From 77b566aaa181bf05f6bb0932624369c6ed99c6d5 Mon Sep 17 00:00:00 2001
From: Harinn <prinn.dev@pm.me>
Date: Sat, 9 May 2026 17:03:38 +0700
Subject: [PATCH] eresi: fix build with gcc 15

---
 pkgs/by-name/er/eresi/package.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/by-name/er/eresi/package.nix b/pkgs/by-name/er/eresi/package.nix
index 97b7e50c295e..d1b8470c2d45 100644
--- a/pkgs/by-name/er/eresi/package.nix
+++ b/pkgs/by-name/er/eresi/package.nix
@@ -40,6 +40,9 @@ stdenv.mkDerivation (finalAttrs: {
     })
   ];
 
+  # K&R-style function-pointer declarations break under gcc 15's C23 default.
+  env.NIX_CFLAGS_COMPILE = "-std=gnu17";
+
   postPatch = ''
     # Two occurences of fprintf() with only two arguments, which should really
     # be fputs().