Not buildable with macOS <= 10.9 #648
Description
It seems that Rustix isn't buildable against versions of the macOS SDK <= 10.9, which don't provide some of the *at filesystem calls:
= note: Undefined symbols for architecture x86_64:
"_renameat", referenced from:
rustix::backend::fs::syscalls::renameat::h2c0c0bdc5b1b53dd in librustix-8716fc0ada80f679.rlib(rustix-8716fc0ada80f679.rustix.c8295d04-cgu.2.rcgu.o)
"_unlinkat", referenced from:
rustix::backend::fs::syscalls::unlinkat::h64403488044b3003 in librustix-8716fc0ada80f679.rlib(rustix-8716fc0ada80f679.rustix.c8295d04-cgu.2.rcgu.o)
"_linkat", referenced from:
rustix::backend::fs::syscalls::linkat::h944058f8262ceb1d in librustix-8716fc0ada80f679.rlib(rustix-8716fc0ada80f679.rustix.c8295d04-cgu.2.rcgu.o)
ld: symbol(s) not found for architecture x86_64
clang-14: error: linker command failed with exit code 1 (use -v to see invocation)
This is from a conda-forge build of Tectonic. During package builds, conda-forge sets the MACOSX_SDK_VERSION and MACOSX_DEPLOYMENT_TARGET environment variables to 10.9 in an effort to produce binaries that are widely portable.
This is an old OS version, of course, and if there isn't any interest in attaining/maintaining compatibility with it, I'll understand. But I thought I'd flag the issue so it's at least documented.