gnome.atomix: pull upstream fix for -fno-common toolchains

Without the change build on -fno-common toolchains fails as:

    $ nix build --impure --expr 'with import ~/nm {}; gnome.atomix.override { stdenv = clang13Stdenv; }'
    ld: src/libatomix.a.p/canvas_helper.c.o: undefined reference to symbol 'ceil@@GLIBC_2.2.5'
    ld: /nix/store/m4g6lswi75b739cpdx8wfxlfmcazyks9-glibc-2.34-115/lib/libm.so.6: error adding symbols: DSO missing from command line

pkgs/desktops/gnome/games/atomix/default.nix

@@ -1,4 +1,5 @@
-{ lib, stdenv, fetchurl, meson, ninja, pkg-config, wrapGAppsHook, python3
+{ lib, stdenv, fetchurl, fetchpatch
+, meson, ninja, pkg-config, wrapGAppsHook, python3
 , gettext, gnome, glib, gtk3, libgnome-games-support, gdk-pixbuf }:
 
 stdenv.mkDerivation rec {
@@ -10,9 +11,24 @@ stdenv.mkDerivation rec {
     sha256 = "0h909a4mccf160hi0aimyicqhq2b0gk1dmqp7qwf87qghfrw6m00";
   };
 
+  patches = [
+    # Pull upstream fix for -fno-common toolchains like gcc-10:
+    #  https://gitlab.gnome.org/GNOME/atomix/-/merge_requests/2
+    (fetchpatch {
+      name = "fno-common.patch";
+      url = "https://gitlab.gnome.org/GNOME/atomix/-/commit/be7f44f1945a569494d46c60eaf6e7b39b2bb48b.patch";
+      sha256 = "0nrwl6kb1als9mxd5s0la45z63xwshqlnxqjaax32w8yrl6kz7l8";
+    })
+  ];
+
   nativeBuildInputs = [ meson ninja pkg-config gettext wrapGAppsHook python3 ];
   buildInputs = [ glib gtk3 gdk-pixbuf libgnome-games-support gnome.adwaita-icon-theme ];
 
+  # When building with clang ceil() is not inlined:
+  # ld: src/libatomix.a.p/canvas_helper.c.o: undefined reference to symbol 'ceil@@GLIBC_2.2.5'
+  #  https://gitlab.gnome.org/GNOME/atomix/-/merge_requests/3
+  NIX_LDFLAGS = "-lm";
+
   postPatch = ''
     chmod +x meson_post_install.py
     patchShebangs meson_post_install.py