[MacPorts] #61636: OpenBLAS @0.3.12-universal: Dependencies fail to install on ARM64

[MacPorts]

#61636: OpenBLAS @0.3.12-universal: Dependencies fail to install on ARM64
-----------------------+---------------------------------------
  Reporter:  jpanetta  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.6.4
Resolution:            |   Keywords:  arm64, M1, icu, universal
      Port:  OpenBLAS  |
-----------------------+---------------------------------------

Comment (by jpanetta):

 I think it actually was `ld64` asking for `llvm-9.0`, and it's `gcc10`
 asking for `ld64`.

 `llvm-9.0` actually built fine for me after those changes I mentioned
 above. But then `ld64` also was missing `arm64`, and adding it was
 significantly trickier (I had to update to `ld64-530`, since backporting
 arm64 support to `ld64-450` looked too difficult). I was able to get 530
 working with the attached hacked-together patches. One surprise is the
 `rebase` binary seems to have been dropped.

 Walking up the dependency tree, now I'm blocked by gcc10, which just says:
 {{{
 error:fetch gcc10 10.2.0 is not supported on Darwin 20 arm
 error:fetch Failed to fetch libgcc10: incompatible OS X version
 debug:fetch Error code: NONE
 debug:fetch Backtrace: incompatible OS X version
 }}}

 :(

-- 
Ticket URL: <https://trac.macports.org/ticket/61636#comment:13>
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