Comment 1:

Labels changed: added go1.2maybe.

Comment 2:

I disagree. You want a warning because you don't want it disabled.
But when I cross-compile I am happy to have it disabled automatically,
because otherwise my build would fail entirely. I don't want to see
a warning telling me about something that, if it weren't true, would cause
even more problems.
One could imagine trying to second-guess a build failure and say well
if cgo was implicitly disabled and there are cgo files then maybe we 
could say (cgo is disabled) somewhere. But there's no guarantee that the
problem is cgo being disabled and not, say, a syntax error in the non-cgo
version of the code. It's very hard to be sure the added text is helping and
not confusing things more.
I also don't see why cgo should be different from all the other possible build
constraints.

Status changed to Unfortunate.