[MacPorts] #57196: libgcc7 fails to compile/install on macOS Mojave

[MacPorts]

#57196: libgcc7 fails to compile/install on macOS Mojave
------------------------------+--------------------
  Reporter:  ProgrammingPoet  |      Owner:  (none)
      Type:  defect           |     Status:  new
  Priority:  Normal           |  Milestone:
 Component:  ports            |    Version:  2.5.3
Resolution:                   |   Keywords:  mojave
      Port:  libgcc7          |
------------------------------+--------------------

Comment (by tenomoto):

 I had a similar problem with libgcc8 and followed Ryan's suggestion, but
 the same error occurred. I installed system headers (see
 https://solarianprogrammer.com/2017/05/21/compiling-gcc-macos/). Although
 the build is still going, it seems that it passed the point of error.

-- 
Ticket URL: <https://trac.macports.org/ticket/57196#comment:2>
MacPorts <https://www.macports.org/>
Ports system for macOS