[MacPorts] #61584: Use deployment target 10.16 on Big Sur

[MacPorts]

#61584: Use deployment target 10.16 on Big Sur
--------------------------+----------------------------
  Reporter:  ryandesign   |      Owner:  (none)
      Type:  enhancement  |     Status:  new
  Priority:  High         |  Milestone:  MacPorts 2.7.0
 Component:  base         |    Version:  2.6.4
Resolution:               |   Keywords:  bigsur
      Port:               |
--------------------------+----------------------------

Comment (by mcmara):

 I think the relevant error may be this line in the ```gdk-pixbuf2``` build
 log:

 {{{
 :info:build distutils.errors.DistutilsPlatformError:
 $MACOSX_DEPLOYMENT_TARGET mismatch: now "10.16" but "11.0" during
 configure
 }}}

 I solved by commenting out the line '''macosx_deployment_target 10.16'''
 while building bots that depend on it.

-- 
Ticket URL: <https://trac.macports.org/ticket/61584#comment:8>
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