[boost] cross-compiling linux->osx: file was built for archive which is not the architecture being linked (x86_64)

Subject: [boost] cross-compiling linux->osx: file was built for archive which is not the architecture being linked (x86_64)
From: Frédéric Bron (frederic.bron_at_[hidden])
Date: 2016-11-08 01:21:21

I am trying to cross-compile for osx from linux using clang.

When I build boost, I use the following:
CC="x86_64-apple-darwin13-clang" CFLAGS="-O2 -DNDEBUG"
CXX="x86_64-apple-darwin13-clang++-libc++" CXXFLAGS="-O2 -DNDEBUG
-std=c++14" AR="x86_64-apple-darwin13-ar"
AS="x86_64-apple-darwin13-as" RANLIB="x86_64-apple-darwin13-ranlib"
./bootstrap.sh --without-icu
--prefix=/softs/usr/darwin13-clang/release/boost --with-toolset=clang

Then I use the following user-config.jam:

using clang : : x86_64-apple-darwin13-clang++-libc++ : <cxxflags>-std=c++14 ;

with the following command:

./b2 -d2 -j8 --layout=system --user-config=user-config.jam
--without-mpi --without-python --without-context --without-coroutine
link=static threading=multi runtime-link=shared target-os=darwin
threadapi=pthread address-model=64 define=BOOST_THREAD_USE_LIB
define=BOOST_LOG_WITHOUT_EVENT_LOG variant=release install

Apart from a few errors, everythings looks fine:

...failed updating 3 targets...
...skipped 3 targets...
...updated 13684 targets...

However, when I link against the static libraries that have been
built, I get this type of messages:

ld: warning: ignoring file
/softs/usr/darwin13-clang/release/boost/lib/libboost_system.a, file
was built for archive which is not the architecture being linked
(x86_64): /softs/usr/darwin13-clang/release/boost/lib/libboost_system.a

I suspect that it is because the wrong ar and ranlib where used
because I find in my log that b2 used "ar" and "ranlib" instead of
"x86_64-apple-darwin13-ar" and "x86_64-apple-darwin13-ranlib".

So I changed my user-config.jam to:

using clang : : x86_64-apple-darwin13-clang++-libc++ :
<cxxflags>-std=c++14 <archiver>x86_64-apple-darwin13-ar
<ranlib>x86_64-apple-darwin13-ranlib ;

but b2 is still using "ar" and "ranlib".

Any idea of what my problem is?

Frédéric