i386 builds are failing to build on kinetic sizeof(json_transport::json_t) == 16

[tfoote]

It looks like there's an assumption about the size of the data that doesn't hold on 32bit vs the 64. Though oddly it works for amd64, arm64, armhf(32) but not i386. See the downstream here: http://build.ros.org/view/Kbin_uX32/job/Ksrc_uX__json_transport__ubuntu_xenial__source/

From the latest build: http://build.ros.org/view/Kbin_uX32/job/Kbin_uX32__json_transport__ubuntu_xenial_i386__binary/326/console

[ 50%] Building CXX object CMakeFiles/test_listener_cpp.dir/test/test_listener.cpp.o
/usr/lib/ccache/i686-linux-gnu-g++   -DROSCONSOLE_BACKEND_LOG4CXX -DROS_PACKAGE_NAME=\"json_transport\" -I/tmp/binarydeb/ros-kinetic-json-transport-0.0.1/include -I/opt/ros/kinetic/include -I/opt/ros/kinetic/share/xmlrpcpp/cmake/../../../include/xmlrpcpp  -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -DNDEBUG -Wdate-time -D_FORTIFY_SOURCE=2    -std=c++14 -Wall -Werror -o CMakeFiles/test_listener_cpp.dir/test/test_listener.cpp.o -c /tmp/binarydeb/ros-kinetic-json-transport-0.0.1/test/test_listener.cpp
In file included from /tmp/binarydeb/ros-kinetic-json-transport-0.0.1/test/test_listener.cpp:31:0:
/tmp/binarydeb/ros-kinetic-json-transport-0.0.1/include/json_transport/json_transport.hpp:45:1: error: static assertion failed: sizeof(json_transport::json_t) == 16
 ROS_STATIC_ASSERT(sizeof(json_transport::json_t) == 16);
 ^
CMakeFiles/test_listener_cpp.dir/build.make:65: recipe for target 'CMakeFiles/test_listener_cpp.dir/test/test_listener.cpp.o' failed
make[4]: Leaving directory '/tmp/binarydeb/ros-kinetic-json-transport-0.0.1/obj-i686-linux-gnu'
make[4]: *** [CMakeFiles/test_listener_cpp.dir/test/test_listener.cpp.o] Error 1
make[3]: *** [CMakeFiles/test_listener_cpp.dir/all] Error 2
make[2]: *** [all] Error 2
CMakeFiles/Makefile2:201: recipe for target 'CMakeFiles/test_listener_cpp.dir/all' failed

[paulbovbel]

I'm sorry I took so long to respond to this @tfoote, it dropped off my radar. Would it make sense just to pull this package from kinetic? I'd rather not dive in otherwise.