Comment by jasomill
5 hours ago
And just to add insult to injury, you probably don't want MINGW64 either, as it relies on the ancient MSVCRT.DLL C runtime library that lacks support for "new" features like C99 compatibility and the UTF-8 locale, and that Microsoft never supported for use by third-party applications in the first place.
Instead, you either want UCRT64 or CLANG64, depending on whether you want to build with the GNU or LLVM toolchains, as it uses the newer, fully-supported Universal C Runtime instead.
It's still useful to use MSVCRT in certain circumstances, such as targeting the earliest 64-bit versions of Windows.
As for UTF-8 support, it's the manifest file that determines whether Windows sets the ANSI code page to UTF-8. (There's also an undocumented API function that resets the code page for GetACP and the Rtl functions that convert ANSI into Unicode. But this would run after all the other DLLs have finished loading.) Having the code page correct is enough to support Unicode filenames and Unicode text in the GUI.
It just won't provide UTF-8 locale support for the standard C library.