opam build problem on MacOS / Xcode

Issue #5 (closed) of the same name has been fixed and incorporated into github repository, but is not yet released in opam. I posted a note sometime back on the closed issue. Could you please release the changes on opam?

thanks!

`The following actions will be performed:
- install proj4 0.9.2

<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[proj4.0.9.2] found in cache

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[ERROR] The compilation of proj4 failed at
"/Users/mhayden/.opam/opam-init/hooks/sandbox.sh build ocaml setup.ml
-build".

#=== ERROR while compiling proj4.0.9.2 ========================================#
# context 2.0.5 | macos/x86_64 | ocaml-variants.4.08.0+flambda+no-flat-float-array | https://opam.ocaml.org/#513397db
# path ~/.opam/macos.dev2/.opam-switch/build/proj4.0.9.2
# command ~/.opam/opam-init/hooks/sandbox.sh build ocaml setup.ml -build
# exit-code 1
# env-file ~/.opam/log/proj4-52462-05296d.env
# output-file ~/.opam/log/proj4-52462-05296d.out
### output ###
# src/proj4_stubs.c:42:5: warning: use of GNU old-style field designator extension [-Wgnu-designator]
# [...]
# src/proj4_stubs.c:43:5: warning: use of GNU old-style field designator extension [-Wgnu-designator]
# serialize: custom_serialize_default,
# ^~~~~~~~~~
# .serialize =
# src/proj4_stubs.c:44:5: warning: use of GNU old-style field designator extension [-Wgnu-designator]
# deserialize: custom_deserialize_default
# ^~~~~~~~~~~~
# .deserialize =
# 6 warnings and 1 error generated.
# Command exited with code 2.
# E: Failure("Command ''/Users/mhayden/.opam/macos.dev2/bin/ocamlbuild' src/libproj4_stubs.a src/dllproj4_stubs.so src/proj4.cma src/proj4.cmxa src/proj4.a src/proj4.cmxs -tag debug' terminated with error code 10")

<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+- The following actions failed
| - build proj4 0.9.2
+-
- No changes have been performed
sakhalin% `