[MacPorts] #54149: gcc6 fails to compile because "configure: error: cannot compute sizeof (long long)"

[René J.V. Bertin]

On Thursday May 18 2017 19:05:31 Ryan Schmidt wrote:

>Yes. Therefore, we need to add a libgcc6 subport, much like the existing libgcc45 subport.

That seems like a small change to port:gcc6, almost easier than removing the libgcc subport completely.
But why is this handled differently that any other port that installs a library with a new ABI or name, when dependent ports just have to put up, revbump and rebuild?
Is that under a (proven?) assumption that some applications cannot be rebuilt against the new ABI? I don't see evidence of a dragonegg port based on gcc6 so that cannot be the reason. 



FWIW, I'm also working on a (PoC) implementation of my idea to provide users who build from source with an option to get both ports from a single build. I'll present that as a separate patch to the Portfile. I have the impression that gcc7 took considerably longer to build than gcc6 so such an option would be timely for those users.

R.