commit b79ed41 regressed spdlog build

[tycho]

I just did a rebase of my project, including latest upstream fmt and spdlog (the latter uses fmt). It appears that fmt broke compatibility with spdlog somehow, but my C++ template-fu is weak and I'm not sure what the error message is trying to tell me exactly:

In file included from code/app.cpp:1:
In file included from code/lib/universal_include.h:450:
In file included from /Users/steven/Development/game/contrib/spdlog/include/spdlog/spdlog.h:14:
/Users/steven/Development/game/contrib/spdlog/include/spdlog/logger.h:375:13: error: no matching function for call to 'vformat_to'
            fmt::detail::vformat_to(buf, fmt, fmt::make_format_args(std::forward<Args>(args)...));
            ^~~~~~~~~~~~~~~~~~~~~~~
/Users/steven/Development/game/contrib/spdlog/include/spdlog/logger.h:90:9: note: in instantiation of function template specialization 'spdlog::logger::log_<const char *>' requested here
        log_(loc, lvl, fmt, std::forward<Args>(args)...);
        ^
code/app.cpp:114:2: note: in instantiation of function template specialization 'spdlog::logger::log<const char *>' requested here
        SPDLOG_LOGGER_INFO(s_logApp, "Version: {}", Game::Version::AnnotatedVersion());
        ^
/Users/steven/Development/game/contrib/spdlog/include/spdlog/spdlog.h:318:45: note: expanded from macro 'SPDLOG_LOGGER_INFO'
#    define SPDLOG_LOGGER_INFO(logger, ...) SPDLOG_LOGGER_CALL(logger, spdlog::level::info, __VA_ARGS__)
                                            ^
/Users/steven/Development/game/contrib/spdlog/include/spdlog/spdlog.h:296:58: note: expanded from macro 'SPDLOG_LOGGER_CALL'
#define SPDLOG_LOGGER_CALL(logger, level, ...) (logger)->log(spdlog::source_loc{__FILE__, __LINE__, SPDLOG_FUNCTION}, level, __VA_ARGS__)
                                                         ^
/Users/steven/Development/game/build/game.x86_64-clang-macos-x86_64-debug/contrib/include/fmt/format.h:4120:6: note: candidate template ignored: could not match 'basic_format_args' against 'format_arg_store'
void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
     ^

git bisection blames commit b79ed41:

commit b79ed4105ab2ee268cfdf056aed5b7fb4c09dcb8
Author: Victor Zverovich <[email protected]>
Date:   Thu Sep 1 16:14:53 2022 -0700

    Remove unnecessary type_identity

Here's the bisection log:

$ git bisect log
# bad: [ecffca672656d6e4a2d39314237289f5740e8562] Don't parse '}' as fill
# good: [541cd218381493728241fcc690e8c362434a37ea] Fix locale name (thanks Mikhail Paulyshka)
git bisect start 'ecffca672656d6e4a2d39314237289f5740e8562' '541cd218381493728241fcc690e8c362434a37ea'
# good: [a07411c2b9c440ce0879deeb05774b19bdc48dd2] Disable compile-time checks for dynamic width/precision test for LCC and compiler without std::is_constant_evaluated()
git bisect good a07411c2b9c440ce0879deeb05774b19bdc48dd2
# bad: [f187274d3637403e1391deb69233b34b5e345d37] Add loc_value
git bisect bad f187274d3637403e1391deb69233b34b5e345d37
# bad: [48327a82e335fda96eb184602d84c562ddb372c2] Make format.h compile faster
git bisect bad 48327a82e335fda96eb184602d84c562ddb372c2
# good: [0b0f7cfbfcebd021c910078003d413354bd843e2] hip workaround
git bisect good 0b0f7cfbfcebd021c910078003d413354bd843e2
# bad: [b79ed4105ab2ee268cfdf056aed5b7fb4c09dcb8] Remove unnecessary type_identity
git bisect bad b79ed4105ab2ee268cfdf056aed5b7fb4c09dcb8
# good: [64e29893cfd3a603b79e38d75384e12336e8b980] Improve locale support
git bisect good 64e29893cfd3a603b79e38d75384e12336e8b980
# first bad commit: [b79ed4105ab2ee268cfdf056aed5b7fb4c09dcb8] Remove unnecessary type_identity

It reverts cleanly, which does unblock me, but I figured I should pass this along. Is this spdlog's bug, or fmt's?

[vitaut]

Thanks for reporting but fmt::detail::vformat_to is an internal API and shouldn't be used. Please open an issue in spdlog.

[tycho]

Thanks for reporting but fmt::detail::vformat_to is an internal API and shouldn't be used. Please open an issue in spdlog.

Thank you for the fast reply! I will do so.