[MacPorts] #71577: graphviz, graphviz-devel @12.2.1: error: A compiler with support for C++17 language features is required (was: graphviz, Xcode 16)

[MacPorts]

#71577: graphviz, graphviz-devel @12.2.1: error: A compiler with support for C++17
language features is required
---------------------------------------+----------------------
  Reporter:  dirkx                     |      Owner:  mascguy
      Type:  defect                    |     Status:  assigned
  Priority:  Normal                    |  Milestone:
 Component:  ports                     |    Version:  2.10.5
Resolution:                            |   Keywords:
      Port:  graphviz, graphviz-devel  |
---------------------------------------+----------------------
Changes (by ryandesign):

 * status:  new => assigned
 * cc: ryandesign (added)
 * priority:  Low => Normal
 * milestone:  MacPorts Future =>
 * owner:  (none) => mascguy
 * port:  graphviz => graphviz, graphviz-devel


Old description:

> It appears that Graphviz @12.2.1_0 on Sequoia needs a newer compiler on
> ports version Version: 2.10.5.
>
> Using clang 19 from ports as in:
>
>         sudo port install graphviz configure.cxx=clang++-mp-19
>
> makes it compile again (otherwise it would error out with a
> "configure:19965: error:  A compiler with support for C++17 language
> features is required." after it could not compile "conftest.cpp:450:10:
> fatal error: 'initializer_list' file not found").

New description:

 It appears that Graphviz @12.2.1_0 on Sequoia needs a newer compiler on
 ports version Version: 2.10.5.

 Using clang 19 from ports as in:

 {{{
 sudo port install graphviz configure.cxx=clang++-mp-19
 }}}

 makes it compile again (otherwise it would error out with a
 "configure:19965: error:  A compiler with support for C++17 language
 features is required." after it could not compile "conftest.cpp:450:10:
 fatal error: 'initializer_list' file not found").

--

Comment:

 The Portfile already contains the line `compiler.cxx_standard 2017` so
 MacPorts has already selected a compiler that supports C++17. According to
 CompilerSelection C++17 support is available in Apple Clang 1000 and
 later. According to XcodeVersionInfo that means you should not have a
 problem with Apple Clang from Xcode 10 or later so you shouldn't be seeing
 this problem on Sequoia or Sonoma or even on Ventura, Monterey, Big Sur,
 Catalina, or Mojave. The fact that you are suggests graphviz requires
 ''more'' than just a C++17 compiler. Please attach the main.log file and
 config.log file from the failed build so we can investigate what the real
 requirements are. We had successful builds of this port on Lion and later
 on the buildbot so the problem may be specific to your computers.

-- 
Ticket URL: <https://trac.macports.org/ticket/71577#comment:2>
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