[MacPorts] #66549: qt511-qtimageformats @5.11.3_2: Could not resolve SDK Path for 'macosx10.11' using --show-sdk-path

[MacPorts]

#66549: qt511-qtimageformats @5.11.3_2: Could not resolve SDK Path for
'macosx10.11' using --show-sdk-path
-----------------------------------+---------------------------------
  Reporter:  thetrial              |      Owner:  MarcusCalhoun-Lopez
      Type:  defect                |     Status:  assigned
  Priority:  Normal                |  Milestone:
 Component:  ports                 |    Version:  2.8.0
Resolution:                        |   Keywords:  elcapitan legacy-os
      Port:  qt511-qtimageformats  |
-----------------------------------+---------------------------------

Comment (by MarcusCalhoun-Lopez):

 As far as I can tell, the main problem is `QMAKE_MAC_SDK`.\\
 Qt uses to find tools
 (https://code.qt.io/cgit/qt/qtbase.git/tree/mkspecs/features/mac/sdk.prf?h=5.15).\\
 The best we may be able to do is set `QMAKE_MAC_SDK` to
 `macosx${configure.sdk_version}` if possible, otherwise default to
 `macosx`.

 There is a [https://github.com/macports/macports-ports/pull/17223 pull
 request] that attempts this.\\
 I am sure the new procedure `qt5pg::qmake_mac_sdk` could be improved, but
 I just used a copied `configure_get_sdkroot` from base.

-- 
Ticket URL: <https://trac.macports.org/ticket/66549#comment:32>
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