At this moment it is not possible to use cross-toolchains to build
32-bit software with using `gcc -m32`. For example the following simple
code fails to be compiled if libc6-dev-i386 and gcc-multilib are not
installed. Installing gcc-multilib conflicts with installtion of all the
cross-toolchains (including, but not limited to gcc-aarch64-linux-gnu
gcc-arm-linux-gnueabi gcc-arm-linux-gnueabihf), which I use for the
dailyjob. It would be really nice to be able to use i686-cross toolchain
to be used for `gcc -m32` support.

[For the reference: the need for gcc -m32 comes from the need to build
luajit for arm, which requires the several host tools to be compiled
with the same pointer size as the target pointer size.]

===== CUT test.c ======
#include <sys/types.h>
#include <errno.h>
int main(void) { return 0; }
===== CUT test.c ======