Fix build with llvm 22 for several packages (#494634)

pkgs/by-name/db/dbus/package.nix

@@ -127,6 +127,7 @@ stdenv.mkDerivation (finalAttrs: {
     (lib.mesonEnable "launchd" stdenv.hostPlatform.isDarwin)
     (lib.mesonEnable "systemd" enableSystemd)
     "-Dselinux=disabled"
+    "-Dc_args=-Wno-error=incompatible-pointer-types"
   ]
   ++ lib.optionals stdenv.hostPlatform.isDarwin [
     # D-Bus defaults to launchd-activation on Darwin, but that requires the launch agent be installed. It also breaks

pkgs/by-name/fo/fontforge/package.nix

@@ -82,7 +82,12 @@ stdenv.mkDerivation (finalAttrs: {
   '';
 
   # do not use x87's 80-bit arithmetic, rounding errors result in very different font binaries
-  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.hostPlatform.isi686 "-msse2 -mfpmath=sse";
+  env.NIX_CFLAGS_COMPILE = lib.join " " (
+    [
+      "-Wno-error=incompatible-pointer-types"
+    ]
+    ++ lib.optional stdenv.hostPlatform.isi686 "-msse2 -mfpmath=sse"
+  );
 
   strictDeps = true;
 

pkgs/by-name/gb/gbenchmark/package.nix

@@ -52,7 +52,12 @@ stdenv.mkDerivation (finalAttrs: {
     #
     # This might be a problem with our Clang, as it does not reproduce
     # with Xcode, but we just work around it by silencing the warning.
-    NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-c++17-attribute-extensions";
+    NIX_CFLAGS_COMPILE = lib.join " " (
+      [
+        "-Wno-error=c2y-extensions"
+      ]
+      ++ lib.optional stdenv.cc.isClang "-Wno-c++17-attribute-extensions"
+    );
   }
   // lib.optionalAttrs stdenv.hostPlatform.isGnu {
     # For test:locale_impermeability_test

pkgs/os-specific/darwin/by-name/ad/adv_cmds/package.nix

@@ -74,8 +74,10 @@ mkAppleDerivation {
         --replace-fail '/usr/local' "$out"
     done
   '';
-
-  env.NIX_CFLAGS_COMPILE = "-I${privateHeaders}/include";
+  env.NIX_CFLAGS_COMPILE = lib.join " " [
+    "-I${privateHeaders}/include"
+    "-Wno-error=incompatible-pointer-types"
+  ];
 
   buildInputs = [
     libxo