https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95131
--- Comment #3 from Trass3r <trass3r at gmail dot com> --- Well sure but most existing codebases won't be ported to modules because of the effort while enabling pch is now straightforward with latest CMake. These conformance issues have also been identified in https://reviews.llvm.org/D69585#1946765, which is why a flag -fpch-instantiate-templates was suggested. For C++20 header unit compilation this behavior is actually required it seems, so at least if -fmodule-header reuses pch code this may be a low-hanging fruit. Is anything else from the wiki valid? "Mangle names, instantiate templates, and generate debug information at pch generation time"
