From 4b9dc0116fe69b880b7b4b7f37552de9bc7a91aa Mon Sep 17 00:00:00 2001
From: Justin Chen <42143810+StarryReverie@users.noreply.github.com>
Date: Tue, 6 Jan 2026 22:12:45 +0800
Subject: [PATCH] pcalc: fix build with GCC 15

---
 pkgs/by-name/pc/pcalc/package.nix | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pkgs/by-name/pc/pcalc/package.nix b/pkgs/by-name/pc/pcalc/package.nix
index 2cecb56e3d01..b59ed2da4bd6 100644
--- a/pkgs/by-name/pc/pcalc/package.nix
+++ b/pkgs/by-name/pc/pcalc/package.nix
@@ -17,6 +17,11 @@ stdenv.mkDerivation {
     sha256 = "sha256-m4xdsEJGKxLgp/d5ipxQ+cKG3z7rlvpPL6hELnDu6Hk=";
   };
 
+  # Since C23, coercing functions with different parameter lists to a function pointer with no
+  # parameter specified triggers a hard error: `symbol.c:92:22: error: initialization of
+  # 'int (*)(void)' from incompatible pointer type 'int (*)(double)' [-Wincompatible-pointer-types]`
+  env.NIX_CFLAGS_COMPILE = "-std=gnu17";
+
   makeFlags = [ "DESTDIR= BINDIR=$(out)/bin" ];
   nativeBuildInputs = [
     bison