pkg and mpkg

[Ryan Schmidt]

On Feb 8, 2010, at 01:09, Michael Crawford wrote:

> On Sun, Feb 7, 2010 at 12:37 PM, Joshua Root <jmr at macports.org> wrote:
>> Portfiles are Turing complete, so yes, you can in principle install
>> however you like. It seems strange that the software would be able to
>> build against the 10.4 SDK but not actually on < 10.6 though.
> 
> One can build software that uses 10.6 features if they are present,
> but is still compatible with 10.4 and 10.5 provided one doesn't try to
> use features that they didn't support.
> 
> The way this works is that the dynamic linker will set some of the
> system framework function pointers to NULL if they aren't supported by
> the framework.  So it is up to the developer to check the function
> pointers before actually using them.
> 
> I don't know how it would be handled with MacPorts, but with Xcode
> projects one can specify different major releases for the SDK and for
> the deployment target.

Support for building with different SDKs was removed from MacPorts in 1.8.0 because it worked for only a small handful of ports, was more trouble than it was worth, and is not the way we intend users to use MacPorts. (We intend users to install MacPorts and build ports on the same computer that the software will ultimately be used on.)