[MacPorts] #64997: Cannot build libgcc9 under Monterey

[MacPorts]

#64997: Cannot build libgcc9 under Monterey
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  Reporter:  keldhelsgaun  |      Owner:  (none)
      Type:  defect        |     Status:  new
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:
Resolution:                |   Keywords:
      Port:                |
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Comment (by kencu):

 Oh, I see one more thing. Your ports are installed as:

 {{{
 darwin 18
 }}}

 but you are not on darwin18 any more. So this won't work right either.
 When you upgrade your operating system to a new version, you must (sadly)
 uninstall all the ports for the old operating system and then reinstall
 all the ports for the new operating system. Otherwise, unexpected things
 can happen.

 this is such a common FAQ there is a Wiki entry to explain both the issue
 and how to resolve it:

 https://trac.macports.org/wiki/Migration

-- 
Ticket URL: <https://trac.macports.org/ticket/64997#comment:8>
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