gerbil: disable stackprotector on aarch64-darwin for now

pkgs/development/compilers/gerbil/build.nix

@@ -21,6 +21,15 @@ stdenv.mkDerivation rec {
   buildInputs = [ gambit ]
     ++ buildInputs_libraries; # ++ buildInputs_staticLibraries;
 
+  # disable stackprotector on aarch64-darwin for now
+  # build error:
+  # ```
+  # /private/tmp/nix-build-gerbil-unstable-2020-11-05.drv-0/ccjyhWKi.s:326:15: error: index must be an integer in range [-256, 255].
+  #         ldr     x2, [x2, ___stack_chk_guard];momd
+  #                          ^
+  # ```
+  hardeningDisable = lib.optionals (gccStdenv.isAarch64 && gccStdenv.isDarwin) [ "stackprotector" ];
+
   NIX_CFLAGS_COMPILE = "-I${libmysqlclient}/include/mysql -L${libmysqlclient}/lib/mysql";
 
   postPatch = ''