So the gotchas (mostly lifted from those blog posts plus vague memories):ġ) You will probably have to fix whatever cross-compiling bugs have crept into our build system over the last 3.5 years. In any case, I documented what I did at the time here: At the time I was using Apple's gcc on Linux (via the toolwhip project), but presumably we'd just use clang now.
I had this working at some point a few years back, doing OSX builds on Linux, including distcc stuff. I corresponded with bz who had tried this before.