[MacPorts] #60032: MongoDB 4.2.3 fails to build on High Sierra

[MacPorts]

#60032: MongoDB 4.2.3 fails to build on High Sierra
------------------------+------------------------
  Reporter:  rseichter  |      Owner:  ryandesign
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.6.2
Resolution:             |   Keywords:
      Port:  mongodb    |
------------------------+------------------------

Comment (by kencu):

 I thought it would automatically add it for you, but please check to see
 if you have clang-9.0 installed already:
 {{{
 sudo port -v installed | grep clang-9.0 | grep active
 }}}
 if by some chance you don't, then install clang-9.0
 {{{
 sudo port -v install clang-9.0
 }}}
 and then please install mongo again
 {{{
 sudo port -v install mongodb configure.compiler=macports-clang-9.0
 }}}
 if that all fails -- I'm uncertain why. It works for me.

-- 
Ticket URL: <https://trac.macports.org/ticket/60032#comment:9>
MacPorts <https://www.macports.org/>
Ports system for macOS