binary package download ignores macosx_deployment_target set globally

[gallafent]

As evinced in ​https://trac.macports.org/ticket/41589 , the binary packages appear to be built with the macports variable macosx_deployment_target set to 10.9 (or unset, and built on a 10.9 machine).

When a user has set this variable to have a different value, but is still allowing binary ports, the binary ports are downloaded even though they were built with a different value to that specified globally by the user in macports.conf. Thise leads to incompatibilities such as those mentioned above.

Possible solutions to this:

• Force buildfromsource always if macosx_deployment_target is set to other than the current system's OS version (this is very easy and has an overhead only for the user)
• Include the macosx_deployment_target as part of the request data when fetching a binary package (this is harder, and could lead to a proliferation of binary packages, one for each possible value of macosx_deployment_target

Either way, the current situation leads to ports being installed which do not honour the value set in macports.conf, which is clearly a bug.

The workaround is to add a buildfromsource always line to macports.conf then rebuild your system with sudo port -n upgrade --force installed (for example).