[MacPorts] #61580: libdv @1.0.0 build failure with Xcode 12

[MacPorts]

#61580: libdv @1.0.0 build failure with Xcode 12
-----------------------------+-----------------------------
  Reporter:  MaurizioLoreti  |      Owner:  ryandesign
      Type:  defect          |     Status:  accepted
  Priority:  Normal          |  Milestone:
 Component:  ports           |    Version:
Resolution:                  |   Keywords:  bigsur catalina
      Port:  libdv           |
-----------------------------+-----------------------------

Comment (by ryandesign):

 `sched_setscheduler` is a Linux function that has never existed on macOS,
 as far as I can tell, so I'm scratching my head how this ever compiled on
 macOS before.

-- 
Ticket URL: <https://trac.macports.org/ticket/61580#comment:3>
MacPorts <https://www.macports.org/>
Ports system for macOS