variable. The default setting is GODEBUG=cgocheck=1, which implements
reasonably cheap dynamic checks. These checks may be disabled
entirely using GODEBUG=cgocheck=0. Complete checking of pointer
handling, at some cost in run time, is available by setting
GOEXPERIMENT=cgocheck2 at build time.

It is possible to defeat this enforcement by using the unsafe package,

			testClose{nil},
		},
	}, {
		// This file was produced using GNU tar v1.26:
		//	echo "Slartibartfast" > file.txt
		//	ln file.txt hard.txt
		//	tar -b 1 --format=ustar -c -f hardlink.tar file.txt hard.txt
		file: "testdata/hardlink.tar",
		tests: []testFnc{
			testHeader{Header{
				Typeflag: TypeReg,
				Name:     "file.txt",
				Size:     15,
				Mode:     0644,
				Uid:      1000,
				Gid:      100,