The gist of my question is how to cross-compile from an i386 to ARM. It seems like different package installations are hiding previous installations, and the compiler can't find libraries, etc.
I want to cross compile from an i386 machine running Debian 8.7.1 to an ARM machine (a Beaglebone Black, also running Debian). The aim is to use CodeBlocks and wxWidgets with C++ on the i386 to write a GUI which will run on the BBB. Ideally, I want to compile and test entirely on the i386, then flip a few compiler switches to get a version that will run on the BBB once the code is "done" (and periodically during the development process). I'm not totally wed to using CodeBlocks or wxWidgets, though I have experience with both, and I don't think either of those is relevant to the problem I have.
I first installed build-essential, then CodeBlocks, and wxWidgets, and that went fine. All of the sample code that comes with wxWidgets compiled without a hitch and the programs run fine (and still run fine). Then I followed the directions at
http://exploringbeaglebone.com/chapter7/
for installing the packages to allow cross-compiling. Molloy's book is very good, by the way. He has you do
dpkg --add-architecture armhf
apt-get install cross-build-essential-armhf
However, the last step failed due to some missing libraries, which Molloy (the website mentioned) does not discuss, so I installed linux-libc-dev:armhf and libc6-dev:armhf, and the install of cross-build-essential-armhf worked. But it seemed to make g++ (for the i386) disappear so I installed build-essential again (a bad sign).
After the above steps, I can compile (for i386) and cross-compile (for BBB) a simple "hello world" program. However, when I try to compile something which relies on other libraries, the linker can't find them. For example, gthread-2.0, gtk-3, gdk-3, etc., a fairly long list.
Looking at /usr/lib/i386-linux-gnu, it appears that these .so files are there, but the symbolic links have been removed. For instance, libgthread-2.0.so.0 is there, but not a symbolic link to it from libgthread-2.0.so. In fact, libgthread-2.0.so does not exist, though it must have existed (I guess) when the wxWidgets example code was compiled during the wxWidgets installation process.
I could go in and manually create a dozen or more symbolic links that are missing, but I have the feeling that I'm missing some critical element in the big picture of how to cross-compile, and that this kind of manual fix would only be a band-aid on the underlying problem. I also wonder about the fact that /etc/ld.so.conf now includes directories for ARM. Should it?