const O: type = switch (builtin.os.tag) {
    // We want to expose the POSIX-like OFLAGS, so we use std.c.wasi.O instead
    // of std.os.wasi.O, which is for non-POSIX-like `wasi.path_open`, etc.
    .wasi => std.c.O,
    else => system.O,
};