doxygen-devel @1.9.6 does not build on macOS High Sierra, Version 10.13.6, because of 'call to unavailable function 'get': introduced in macOS 10.14'?

[ballapete (Peter "Pete" Dyballa)]

A few times the compiler reports:

/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_doxygen-devel/doxygen-devel/work/doxygen-1.9.6/src/dispatcher.h:63:34: error: call to unavailable function 'get': introduced in macOS 10.14
    std::invoke( W<Alt>::method, std::get<I>( std::forward<V>(v) ), std::forward<As>(args)... );
                                 ^~~~~~~~~~~

In the end get:

warning: unknown warning option '-Wno-implicit-int-conversion' [-Wunknown-warning-option]
1 warning and 6 errors generated.
make[2]: *** [src/CMakeFiles/doxymain.dir/__/generated_src/code.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
1 warning and 6 errors generated.
make[2]: *** [src/CMakeFiles/doxymain.dir/__/generated_src/fortrancode.cpp.o] Error 1
1 warning generated.
1 warning generated.
1 warning generated.
1 warning generated.
1 warning generated.
1 warning generated.
make[2]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_doxygen-devel/doxygen-devel/work/doxygen-1.9.6'
make[1]: *** [src/CMakeFiles/doxymain.dir/all] Error 2
make[1]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_doxygen-devel/doxygen-devel/work/doxygen-1.9.6'
make: *** [all] Error 2
make: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_doxygen-devel/doxygen-devel/work/doxygen-1.9.6'
Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_textproc_doxygen-devel/doxygen-devel/work/doxygen-1.9.6" && /usr/bin/make -j8 -w all VERBOSE=ON 
Exit code: 2

[ballapete (Peter "Pete" Dyballa)]

Main.log from High Sierra 10.13.6

[ryandesign (Ryan Carsten Schmidt)]

Yup. This issue is why the doxygen-devel port was created: to verify whether the doxygen software builds on all systems before updating the doxygen port. Prior to doxygen-devel's creation, the doxygen port was updated to 1.9.4, which didn't compile everywhere, #65314 was filed, and it was reverted to 1.9.3. Later, doxygen was updated to 1.9.5, it didn't build everywhere, #66069 was filed, and it was reverted to 1.9.3 again.

[kencu (Ken)]

In 702aec8498e092f83d05f22e8f17c1ab58f71957/macports-ports (master):

doxygen-devel: use macports-libcxx when needed

closes: #66697