pkg os, method (*PathError) Unwrap() error
pkg os, method (FileMode) IsDir() bool
pkg os, method (FileMode) IsRegular() bool
pkg os, method (FileMode) Perm() FileMode
pkg os, method (FileMode) String() string
pkg os, type FileInfo interface { IsDir, ModTime, Mode, Name, Size, Sys }
pkg os, type FileInfo interface, IsDir() bool
pkg os, type FileInfo interface, ModTime() time.Time

pkg syscall (netbsd-arm64-cgo), const EINVAL = 22
pkg syscall (netbsd-arm64-cgo), const EIO = 5
pkg syscall (netbsd-arm64-cgo), const EISCONN = 56
pkg syscall (netbsd-arm64-cgo), const EISDIR = 21
pkg syscall (netbsd-arm64-cgo), const ELAST = 96
pkg syscall (netbsd-arm64-cgo), const ELAST Errno
pkg syscall (netbsd-arm64-cgo), const ELOOP = 62
pkg syscall (netbsd-arm64-cgo), const EMFILE = 24

func (w *Writer) AddFS(fsys fs.FS) error {
	return fs.WalkDir(fsys, ".", func(name string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if d.IsDir() {
			return nil
		}
		info, err := d.Info()
		if err != nil {
			return err
		}
		if !info.Mode().IsRegular() {
			return errors.New("zip: cannot add non-regular file")
		}

pkg io/fs, method (FileMode) IsDir() bool
pkg io/fs, method (FileMode) IsRegular() bool
pkg io/fs, method (FileMode) Perm() FileMode
pkg io/fs, method (FileMode) String() string
pkg io/fs, method (FileMode) Type() FileMode
pkg io/fs, type DirEntry interface { Info, IsDir, Name, Type }
pkg io/fs, type DirEntry interface, Info() (FileInfo, error)
pkg io/fs, type DirEntry interface, IsDir() bool

pkg os, method (*SyscallError) Error() string
pkg os, method (FileMode) IsDir() bool
pkg os, method (FileMode) Perm() FileMode
pkg os, method (FileMode) String() string
pkg os, type File struct
pkg os, type FileInfo interface { IsDir, ModTime, Mode, Name, Size, Sys }
pkg os, type FileInfo interface, IsDir() bool
pkg os, type FileInfo interface, ModTime() time.Time

	}

	d, err := os.Open(src)
	if err != nil {
		return err
	}
	defer d.Close()
	fi, err := d.Readdir(-1)
	if err != nil {
		return err
	}

	for _, f := range fi {
		if f.IsDir() {
			if f.Name() == "testdata" {
				if err := cp(dst, filepath.Join(src, f.Name())); err != nil {
					return err
				}
			}
			continue
		}

	w.imported[name] = &importing

	// Determine package files.
	dir := w.importDir[name]
	if dir == "" {
		dir = filepath.Join(w.root, filepath.FromSlash(name))
	}
	if fi, err := os.Stat(dir); err != nil || !fi.IsDir() {
		log.Panicf("no source in tree for import %q (from import %s in %s): %v", name, fromPath, fromDir, err)
	}

	context := w.context
	if context == nil {
		context = &build.Default
	}

pkg syscall (freebsd-arm64), const EINTR = 4
pkg syscall (freebsd-arm64), const EINVAL = 22
pkg syscall (freebsd-arm64), const EIO = 5
pkg syscall (freebsd-arm64), const EISCONN = 56
pkg syscall (freebsd-arm64), const EISDIR = 21
pkg syscall (freebsd-arm64), const ELAST = 96
pkg syscall (freebsd-arm64), const ELAST Errno
pkg syscall (freebsd-arm64), const ELOOP = 62
pkg syscall (freebsd-arm64), const EMFILE = 24

pkg syscall (freebsd-riscv64), const EINVAL = 22 #53466
pkg syscall (freebsd-riscv64), const EIO = 5 #53466
pkg syscall (freebsd-riscv64), const EISCONN = 56 #53466
pkg syscall (freebsd-riscv64), const EISDIR = 21 #53466
pkg syscall (freebsd-riscv64), const ELAST = 96 #53466
pkg syscall (freebsd-riscv64), const ELAST Errno #53466
pkg syscall (freebsd-riscv64), const ELOOP = 62 #53466

	tr := NewReader(&buf)

	entries, err := fsys.ReadDir(".")
	if err != nil {
		t.Fatal(err)
	}

	var curfname string
	for _, entry := range entries {
		curfname = entry.Name()
		if entry.IsDir() {
			curfname += "/"
			continue
		}
		hdr, err := tr.Next()
		if err == io.EOF {
			break // End of archive
		}
		if err != nil {
			t.Fatal(err)
		}