[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
 Keywords:          |       Port:  clang-12
--------------------+----------------------
 Building current version of clang-12 fails to build on Mac OS 11.6 (Apple
 M1) in patch stage with the following error:
 {{{
 :error:patch Failed to patch clang-12: can't read
 "gcc_subdirectory_x86_64": no such variable
 :debug:patch Error code: NONE
 :debug:patch Backtrace: can't read "gcc_subdirectory_x86_64": no such
 variable
 :debug:patch     while executing
 :debug:patch "$post $targetname"
 }}}
 Full log is attached.

 This happened during an attempt to restore the port selection from a
 computer running Catalina on a new Mac using the
 [https://trac.macports.org/wiki/Migration Migration procedure].

-- 
Ticket URL: <https://trac.macports.org/ticket/63521>
MacPorts <https://www.macports.org/>
Ports system for macOS