Detect OS upgrades and refer users to Migration

[Joshua Root]

On 2013-11-18 01:11 , Rainer Müller wrote:
> On 2013-11-17 14:44, Ryan Schmidt wrote:
>> Thanks. I see you’re checking OS_PLATFORM and OS_MAJOR. Could we check OS_ARCH as well?
> 
> That's difficult as the distributed pkg installers for Tiger and Leopard
> are universal. Therefore it's not a fixed value, but from a list of
> supported archs.
> 
> However, there is no configure option for that list yes, as only the
> MacPorts Portfile passes multiple -arch options to the compiler and does
> not tell configure about it.

Are there actually any cases where base will not just fail to run when
built for an inappropriate arch? Certainly if you have a ppc
MacPorts.dylib you have to really try to get it to load into the system
tclsh on an Intel machine even when you have Rosetta.

- Josh