Detect OS upgrades and refer users to Migration

[Ryan Schmidt]

On Nov 17, 2013, at 06:57, Rainer Müller wrote:
> On 2013-11-06 17:25, Daniel J. Luke wrote:
>> On Nov 6, 2013, at 5:06 AM, Rainer Müller wrote:
>>> 
>>> As our base system is already targeting a specific OS release, we should
>>> just store the platform it was built for in *_autoconf.tcl and issue an
>>> error if that does not match on launch.
>> 
>> That sounds good to me.
> 
> Implemented now on trunk:
> http://trac.macports.org/changeset/113478

Thanks. I see you’re checking OS_PLATFORM and OS_MAJOR. Could we check OS_ARCH as well?