Changing default cxx_stdlib to libc++

[db]

On 9 Mar 2018, at 15:21, Joshua Root <jmr at macports.org> wrote:
> On 2018-3-9 20:38 , db wrote:
>> On 9 Mar 2018, at 01:27, Ryan Schmidt <ryandesign at macports.org> wrote:
>>> When would we run this script to delete libstdc++ archives? Presumably, after all legacy users have MacPorts 2.5 and have switched to libc++.
>> How about those that build MP from source?
> There are no additional problems arising from that

If I build base and ports from source, will buildfromsource be changed unilaterally by MP or would it need user intervention? I also have certain versions of gcc and llvm locally to avoid rebuilding after minor versions and revbumps.