SDK (isysroot) selection "rules"? (Qt5 related)

[Ryan Schmidt]

On Jun 19, 2015, at 4:32 AM, René J. V. Bertin wote:

> Ryan Schmidt wrote:
> 
>> In most cases, MacPorts doesn't tell build systems to use an SDK.
> 
> What about the deployment target (MACOSX_DEPLOYMENT_TARGET)?

MacPorts always sets the MACOSX_DEPLOYMENT_TARGET environment variable, in every phase, to the value of the MacPorts Tcl variable macosx_deployment_target. The default value of macosx_deployment_target is the currently running OS X major version (like 10.8 or 10.10). It can be changed by the portfile author if needed for a particular port, or globally by the user in macports.conf. The latter is undocumented and unsupported but basically functional.