ocamlPackages.core_extended: fix build on Linux

pkgs/development/ocaml-modules/janestreet/core-extended.nix

@@ -13,6 +13,13 @@ buildOcamlJane rec {
       ppx_assert ppx_bench ppx_driver ppx_expect ppx_inline_test ppx_jane
       re2 textutils ];
 
+  patchPhase = stdenv.lib.optionalString stdenv.isLinux ''
+    patch src/extended_unix_stubs.c <<EOF
+0a1
+> #define _LINUX_QUOTA_VERSION 2
+EOF
+  '';
+
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/core_extended;
     description = "Jane Street Capital's standard library overlay";