[MacPorts] #62816: Buildbot: building XCode project on 10.14.4 fails with: Swift does not support the SDK 'MacOSX10.14.sdk'

[MacPorts]

#62816: Buildbot: building XCode project on 10.14.4 fails with: Swift does not
support the SDK 'MacOSX10.14.sdk'
------------------------+----------------------
  Reporter:  lhaeger    |      Owner:  lhaeger
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.6.4
Resolution:             |   Keywords:
      Port:  AutoRaise  |
------------------------+----------------------

Comment (by lhaeger):

 `configure.sdk_version` and/or `configure.sdkroot` are likely helpful to
 solve the issue, but I need to set it depending on the XCode version used,
 not (only) the macOS version. Anyone trying to build with XCode 10.x on
 macOS 10.14 will have to use the 10.14 SDK, while anyone using XCode 11.x
 on the same macOS 10.14 with need to use SDK 10.15.

 So I'll read up on how to best determine the XCode version next...

-- 
Ticket URL: <https://trac.macports.org/ticket/62816#comment:8>
MacPorts <https://www.macports.org/>
Ports system for macOS