From 91defc8d32dcffdc5664bc2e039d6679497e44b7 Mon Sep 17 00:00:00 2001
From: Phillip Seeber <phillip.seeber@uni-jena.de>
Date: Mon, 12 Jan 2026 13:32:29 +0100
Subject: [PATCH] openmolcas: ensure gcc15 compatibility

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

diff --git a/pkgs/by-name/op/openmolcas/package.nix b/pkgs/by-name/op/openmolcas/package.nix
index c3b43cf20f3e..3630ed9622b6 100644
--- a/pkgs/by-name/op/openmolcas/package.nix
+++ b/pkgs/by-name/op/openmolcas/package.nix
@@ -117,6 +117,9 @@ stdenv.mkDerivation rec {
 
   passthru = lib.optionalAttrs enableMpi { inherit mpi; };
 
+  # fix build with GCC 15
+  env.NIX_CFLAGS_COMPILE = "-std=gnu17";
+
   cmakeFlags = [
     "-DOPENMP=ON"
     "-DTOOLS=ON"