Yeah. I think I’ll end up having to do platform-specific ifdefs with either pthreads or threads.h, so I guess I may as well use the much better established pthreads and get macOS support by default. In fact, I just now learned that even glibc didn’t support C11 threads until 2018, according to this https://sourceware.org/bugzilla/show_bug.cgi?id=14092#c10
Nautilus in general is my biggest gripe with Gnome. I despise it so much that I’m willing to abandon ship to KDE when Plasma 6 reaches my distro.