[MacPorts] #63281: macports-gcc-7 is not selected on libstdc++ systems with compiler.cxx_standard 2017

[MacPorts]

#63281: macports-gcc-7 is not selected on libstdc++ systems with
compiler.cxx_standard 2017
-------------------------------+---------------------
  Reporter:  evanmiller        |      Owner:  dbevans
      Type:  defect            |     Status:  closed
  Priority:  Normal            |  Milestone:
 Component:  base              |    Version:  2.7.1
Resolution:  fixed             |   Keywords:
      Port:  webkit2-gtk gcc7  |
-------------------------------+---------------------
Description changed by ryandesign:

Old description:

> {{{
>  --->  Configuring webkit2-gtk
> Failed to configure webkit2-gtk: Invalid value for configure.compiler:
> }}}
>
> It appears that the GCC7 installed on my system is not recognized as
> supporting C++17 (contrary to
> [https://trac.macports.org/wiki/CompilerSelection Compiler Selection]).
> Manually setting the compiler
>
> {{{
> sudo port configure webkit2-gtk configure.compiler=macports-gcc-7
> }}}
>
> allows configuration to proceed.

New description:

 {{{
  --->  Configuring webkit2-gtk
 Failed to configure webkit2-gtk: Invalid value for configure.compiler:
 }}}

 It appears that the GCC7 installed on my system is not recognized as
 supporting C++17 (contrary to CompilerSelection). Manually setting the
 compiler

 {{{
 sudo port configure webkit2-gtk configure.compiler=macports-gcc-7
 }}}

 allows configuration to proceed.

--

-- 
Ticket URL: <https://trac.macports.org/ticket/63281#comment:7>
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