[MacPorts] #58442: gcc9 (and other gccN) fails to install on Mojave, Xcode-10.2.1

[MacPorts]

#58442: gcc9 (and other gccN) fails to install on Mojave, Xcode-10.2.1
-------------------------+--------------------
  Reporter:  mouse07410  |      Owner:  (none)
      Type:  defect      |     Status:  new
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:
Resolution:              |   Keywords:
      Port:  gcc9        |
-------------------------+--------------------

Comment (by kencu):

 So I had no trouble building `gcc9` on Mojave with Xcode 10.2.1 using the
 default cctools setting as above, without making any Portfile
 modifications.

 Did you force the installation of a different `cctools` variant? If so,
 that is likely your trouble.

 Not that there isn't a problem with `clang-7.0` and `clang-8.0` crashing
 while compiling `gcc9` -- there certainly is, and that will need to be
 eventually fixed upstream in the llvm group somewhere, it would appear.
 But life is too short for taking on every issue every day. Follow the
 "road more travelled" and all that.

-- 
Ticket URL: <https://trac.macports.org/ticket/58442#comment:13>
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