https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121335
--- Comment #3 from kongmingd234 <kongmingd234 at proton dot me> --- g++ -fmodules -std=c++23 -O3 /usr/include/vulkan/vulkan.cppm -c -o /dev/null g++ -fmodules -std=c++23 -O3 /usr/local/src/gcc/installed-here/include/c++/16.0.0/bits/std.cc -c -o /dev/null g++ -fmodules -std=c++23 -O3 vulkan_first_test.cpp -c -o vulkan_first_test.o Sorry for the late response. I could not preprocess the vulkan module interface unit, so I uploaded it unpreprocessed.
