const n = this.writeSync(fd, buf);
				callback(null, n);
			},
			chmod(path, mode, callback) { callback(enosys()); },
			chown(path, uid, gid, callback) { callback(enosys()); },
			close(fd, callback) { callback(enosys()); },
			fchmod(fd, mode, callback) { callback(enosys()); },
			fchown(fd, uid, gid, callback) { callback(enosys()); },
			fstat(fd, callback) { callback(enosys()); },
			fsync(fd, callback) { callback(null); },

pkg syscall (netbsd-arm64-cgo), type Credential struct
pkg syscall (netbsd-arm64-cgo), type Credential struct, Gid uint32
pkg syscall (netbsd-arm64-cgo), type Credential struct, Groups []uint32
pkg syscall (netbsd-arm64-cgo), type Credential struct, NoSetGroups bool
pkg syscall (netbsd-arm64-cgo), type Credential struct, Uid uint32
pkg syscall (netbsd-arm64-cgo), type Dirent struct

		{call: "Setegid(0)", fn: func() error { return syscall.Setegid(0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"},

		{call: "Seteuid(1)", fn: func() error { return syscall.Seteuid(1) }, filter: "Uid:", expect: "\t0\t1\t0\t1"},
		{call: "Setuid(0)", fn: func() error { return syscall.Setuid(0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"},

		headers: []*Header{{
			Name:     "small.txt",
			Mode:     0640,
			Uid:      73025,
			Gid:      5000,
			Size:     5,
			ModTime:  time.Unix(1244428340, 0),
			Typeflag: '0',
			Uname:    "dsymonds",
			Gname:    "eng",
			Format:   FormatGNU,
		}, {
			Name:     "small2.txt",
			Mode:     0640,
			Uid:      73025,
			Gid:      5000,
			Size:     11,
			ModTime:  time.Unix(1244436044, 0),

	verifyString(h.Gname, len(ustar.groupName()), "Gname", paxGname)
	verifyNumeric(h.Mode, len(v7.mode()), "Mode", paxNone)
	verifyNumeric(int64(h.Uid), len(v7.uid()), "Uid", paxUid)
	verifyNumeric(int64(h.Gid), len(v7.gid()), "Gid", paxGid)
	verifyNumeric(h.Size, len(v7.size()), "Size", paxSize)
	verifyNumeric(h.Devmajor, len(ustar.devMajor()), "Devmajor", paxNone)

		used[f.Name] = true
	}

	if !*godefs {
		for cid, goid := range ident {
			if token.Lookup(goid).IsKeyword() {
				// Avoid keyword
				goid = "_" + goid

				// Also avoid existing fields
				for _, exist := used[goid]; exist; _, exist = used[goid] {
					goid = "_" + goid
				}

				used[goid] = true
				ident[cid] = goid
			}
		}
	}

	anon := 0

//	Name              |   256B | unlimited | unlimited
//	Linkname          |   100B | unlimited | unlimited
//	Size              | uint33 | unlimited |    uint89
//	Mode              | uint21 |    uint21 |    uint57
//	Uid/Gid           | uint21 | unlimited |    uint57
//	Uname/Gname       |    32B | unlimited |       32B
//	ModTime           | uint33 | unlimited |     int89
//	AccessTime        |    n/a | unlimited |     int89

pkg os/user, type UnknownUserError string
pkg os/user, type UnknownUserIdError int
pkg os/user, type User struct
pkg os/user, type User struct, Gid string
pkg os/user, type User struct, HomeDir string
pkg os/user, type User struct, Name string
pkg os/user, type User struct, Uid string
pkg os/user, type User struct, Username string
pkg path, func Base(string) string
pkg path, func Clean(string) string

pkg syscall (darwin-arm64), type Credential struct
pkg syscall (darwin-arm64), type Credential struct, Gid uint32
pkg syscall (darwin-arm64), type Credential struct, Groups []uint32
pkg syscall (darwin-arm64), type Credential struct, NoSetGroups bool
pkg syscall (darwin-arm64), type Credential struct, Uid uint32
pkg syscall (darwin-arm64), type Dirent struct
pkg syscall (darwin-arm64), type Dirent struct, Ino uint64

pkg syscall (freebsd-arm64), type Credential struct
pkg syscall (freebsd-arm64), type Credential struct, Gid uint32
pkg syscall (freebsd-arm64), type Credential struct, Groups []uint32
pkg syscall (freebsd-arm64), type Credential struct, NoSetGroups bool
pkg syscall (freebsd-arm64), type Credential struct, Uid uint32
pkg syscall (freebsd-arm64), type Dirent struct
pkg syscall (freebsd-arm64), type Dirent struct, Fileno uint64