dirDeleteDir

fn dirDeleteDir(userdata: ?*anyopaque, dir: Dir, sub_path: []const u8) Dir.DeleteDirError!void {
    const ev: *Evented = @ptrCast(@alignCast(userdata));
    _ = ev;

    var path_buffer: [c.PATH_MAX]u8 = undefined;
    const sub_path_posix = try pathToPosix(sub_path, &path_buffer);

    while (true) switch (c.errno(c.unlinkat(dir.handle, sub_path_posix, c.AT.REMOVEDIR))) {
        .SUCCESS => return,
        .INTR => {},
        .ACCES => return error.AccessDenied,
        .PERM => return error.PermissionDenied,
        .BUSY => return error.FileBusy,
        .FAULT => |err| return errnoBug(err),
        .IO => return error.FileSystem,
        .ISDIR => |err| return errnoBug(err),
        .LOOP => return error.SymLinkLoop,
        .NAMETOOLONG => return error.NameTooLong,
        .NOENT => return error.FileNotFound,
        .NOTDIR => return error.NotDir,
        .NOMEM => return error.SystemResources,
        .ROFS => return error.ReadOnlyFileSystem,
        .EXIST => |err| return errnoBug(err),
        .NOTEMPTY => return error.DirNotEmpty,
        .ILSEQ => return error.BadPathName,
        .INVAL => |err| return errnoBug(err), // invalid flags, or pathname has . as last component
        .BADF => |err| return errnoBug(err), // File descriptor used after closed.
        else => |err| return unexpectedErrno(err),
    };
}