libplacebo @6.338.2_0+opengl+vulkan build failure: std::__1::to_chars undefined

[mrkapqa]

Hello,

when doing "sudo port selfupdate && sudo port upgrade outdated" getting an error for libplacebo

--->  Building libplacebo                                
Error: Failed to build libplacebo: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets if you believe there is a bug.
--->  Some of the ports you installed have notes:
  libomp has the following notes:
    To use this OpenMP library:
     * For clang-3.8+, or clang-3.7 with +openmp variant:
        add "-fopenmp" during compilation / linking.
     * For clang-3.7 without +openmp variant, use:
        "-I/opt/local/include/libomp -L/opt/local/lib/libomp -fopenmp"
  py312-cython has the following notes:
    To make the Python 3.12 version of Cython the one that is run when you execute the commands without a version suffix, e.g. 'cython', run:
    
    port select --set cython cython312

maybe have messed up with an macos update since some things with perl seem also not function well any longer;

thank you very much

[jmroot (Joshua Root)]

:info:build Undefined symbols for architecture x86_64:
:info:build   "std::__1::to_chars(char*, char*, double)", referenced from:
:info:build       _pl_str_print_double in convert.cc.o
:info:build   "std::__1::to_chars(char*, char*, float)", referenced from:
:info:build       _pl_str_print_float in convert.cc.o
:info:build ld: symbol(s) not found for architecture x86_64

[i0ntempest]

Failing in buildbots as well. Maybe open an issue upstream.

[ryandesign (Ryan Carsten Schmidt)]

Only failed on some OS versions. This is probably not an upstream issue. std::to_chars is a standard part of C++17 but probably implemented in part in libc++. The port indicates that it requires a newer MacPorts libc++ on Darwin 18 (macOS 10.14) and older, and the build succeeded on 10.14 and older and on 13 and newer but failed on 10.15–12. My suspicion, therefore, is that you need to use MacPorts libc++ on Darwin 21 (macOS 12) and older. You can test this in CI (on 11 and 12 anyway) by sending a PR.

[i0ntempest]

In 855dfe762475e76834eb6f1a1fab00cd973141af/macports-ports (master):

libplacebo: use mp libcxx on 12.0 and below

Closes: #69767