[MacPorts] #63085: clang-12: compiler-rt build sometimes fails parallel building

[MacPorts]

#63085: clang-12: compiler-rt build sometimes fails parallel building
-----------------------+----------------------
  Reporter:  blair     |      Owner:  kencu
      Type:  defect    |     Status:  assigned
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:
Resolution:            |   Keywords:
      Port:  clang-12  |
-----------------------+----------------------

Comment (by kencu):

 It looks like this error is not actually in make, but in cmake itself.
 cmake is symlinking files using a custom command to do it, and it seems
 like sometimes these trip over each other:

 https://github.com/llvm/llvm-
 project/blob/4c92e31dd0f1bd152eda883af20ff7fbcaa14945/compiler-
 rt/lib/builtins/CMakeLists.txt#L534

 how many cmake processes do we run? I thought only one, so I'm not sure as
 yet how this is colliding with itself.

-- 
Ticket URL: <https://trac.macports.org/ticket/63085#comment:9>
MacPorts <https://www.macports.org/>
Ports system for macOS