pub const Diagnostic = union(enum) {
    none,
    manifest_create: fs.File.OpenError,
    manifest_read: fs.File.ReadError,
    manifest_lock: fs.File.LockError,
    manifest_seek: fs.File.SeekError,
    file_open: FileOp,
    file_stat: FileOp,
    file_read: FileOp,
    file_hash: FileOp,

    pub const FileOp = struct {
        file_index: usize,
        err: anyerror,
    };
}