[MacPorts] #63521: clang-12 @12.0.1 +analyzer+libstdcxx fails in patch stage

[MacPorts]

#63521: clang-12 @12.0.1 +analyzer+libstdcxx fails in patch stage
-----------------------+----------------------
  Reporter:  p-bro     |      Owner:  kencu
      Type:  defect    |     Status:  assigned
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.7.1
Resolution:            |   Keywords:
      Port:  clang-12  |
-----------------------+----------------------

Comment (by kencu):

 Yes, that could happen. On Catalina, clang-12 defaults to using the
 {{{+libstdcxx}}} variant. But on an M1, that variant is not supposed to be
 used so it is not defaulted on:

 https://github.com/macports/macports-
 ports/blob/47a76de2d0f5d7974c8d8ae09fff976b2ec03d56/lang/llvm-12/Portfile#L465

 Please just do this:
 {{{
 sudo port clean clang-12
 sudo port install clang-12
 }}}

 and it should work fine, and then you can go on and restore the rest of
 you list.

 I could make the variant invisible on M1, but I was hoping that we might
 possibly get it to work at some point so I left it as a non-default
 variant that I might come back to work on later.

 But that seems unlikely to ever happen, indeed, so I'll look at just
 making it disappear from M1s.

-- 
Ticket URL: <https://trac.macports.org/ticket/63521#comment:1>
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