https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109688
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Jamaika from comment #4) > https://github.com/gabime/spdlog/blob/v1.x/example/example.cpp > ``` > for %%f in ("example.cpp") do g++.exe -v -std=gnu++20 -march=x86-64-v2 > -ftree-vectorize -g0 -O3 -fPIC -mavx -mxsave -mpclmul -maes > -DSPDLOG_USE_STD_FORMAT=1 -c %%f -o %%~nf.o > ``` That will not work as example.cpp depends on the spdlog headers. PLEASE again have the exact directions on how to test this. Also just like your previous bugs, this is lacking that. Maybe also report the failure to the developer of spdlog since it is not obvious if it is a libstdc++, C++ front-end bug or just a problem with spdlog. Note saying spdlog works with MSVC does not mean it is still not buggy code.