'Unsupported relocation kind 0003' when trying to build zmq-windows with a static MXE

[hcarty]

I'm working on a zeromq package/installation for MXE. It works fine with opam-cross-windows when building against a dynamically linked MXE but not statically (MXE_TARGETS:=x86_64-w64-mingw32.static)

Do you have any suggestions on where to start looking? Based on ocaml/flexdll#29 hinting that SEH could be an issue I tried a fresh MXE build with gcc.mk patched to include --enable-sjlj-exceptions but I get the same error aside from a change in the problematic gcc symbol name from __gxx_personality_seh0 to __gxx_personality_sj0

The error when building zmq-windows with OCaml 4.04.0 from opam-cross-windows:

/home/hcarty/.opam/4.04.0/bin/ocamlfind ocamlmklib -o src/ZMQ_stubs -lzmq src/caml_zmq_stubs.o src/socket.o src/context.o src/fail.o src/poll.o
+ /home/hcarty/.opam/4.04.0/bin/ocamlfind ocamlmklib -o src/ZMQ_stubs -lzmq src/caml_zmq_stubs.o src/socket.o src/context.o src/fail.o src/poll.o
** Fatal error: Unsupported relocation kind 0003 for __gxx_personality_seh0 in /home/hcarty/mxe/usr/x86_64-w64-mingw32.static/lib/libzmq.a(src_libzmq_la-clock.o/

followed by the rest of the .o files in the libzmq.a archive.

[whitequark]

Not really any suggestions. Perhaps use a 32-bit build if you can. I can probably fix flexdll but not quickly and this is not a priority for me. I'd be willing to do this as a contractual item at my usual rate but I'm not sure if this will fit your goals.

[whitequark]

(The above assumes zeromq actually uses exceptions; if not just rebuild with -fno-exceptions, but that seems unlikely to work.)

[hcarty]

Finally got back to this and to my delight -fno-exceptions did the trick. Now there are linking issues with libzmq.a but that doesn't seem to be OCaml-related.

Thank you for the pointer!

[whitequark]

No, this absolutely doesn't mean the issue is solved. Now, assuming zeromq actually does use exceptions, it will simply crash the entire process instead.

[whitequark]

I went through the ZeroMQ source and it doesn't use exceptions as far as I can see, so the fix is fine.

[hcarty]

@whitequark Apologies - I should have been clearer. I also did a search through zeromq's source for anything referencing exceptions before trying the compilation option.