I tend not to like cross-compiling, but sometimes it’s just the simplest solution, particularly if Windows and autotools come into the mix. Recently, I wanted to build xz for Windows, and build it in some particular ways.

windres (the GNU Windows resource compiler) will eat CPPFLAGS, but it won’t process most of them the same way. I often like to use it as a shorthand for both C++ and C compiler options (like -O2), but if windres is in play, only put preprocessor related things. As an example, if you enter -O2 for CPPFLAGS, you get unknown format type `2'.

If you need to target pre-Windows XP, be sure that the compiler is before 7.3. This patch has a hard dependency on a symbol that exists only on XP.

The end result is now I have a cursed xz for an even more cursed operating system: