Code review comment for lp:~dobey/unity8/fix-cross

There's no good solution here yet, so some kind of hack is inevitable if you need cross-building working out of the box right now.

This build-dependency change amounts to build-depending on a specific compiler version only for the build architecture. I can certainly see that it would dodge the problem in this case, but it MUST be annotated with the reasoning (because it is counterintuitive) and as something that could break at any time; in particular with this hack you will get whatever version of g++ happens to be in the build chroots when cross-compiling, which may not be g++-4.9.

https://wiki.debian.org/CrossTranslatableBuildDeps has a list of possible solutions identified at a recent Debian sprint. My understanding is that option 7 (with tweaks to add versions, I think) is the current preferred direction. It does however require changes to compiler packaging before you get to use it.