// starting offset is aligned up to the nearest block edge, and each
// ending offset is aligned down to the nearest block edge.
//
// Even though the Go tar Reader and the BSD tar utility can handle entries
// with arbitrary offsets and lengths, the GNU tar utility can only handle
// offsets and lengths that are multiples of blockSize.
func alignSparseEntries(src []sparseEntry, size int64) []sparseEntry {
	dst := src[:0]
	for _, s := range src {

it is not problematic for the link step to require gcc too.

An important exception is builds using a pre-compiled copy of the
standard library. In particular, package net uses cgo on most systems,
and we want to preserve the ability to compile pure Go code that
imports net without requiring gcc to be present at link time. (In this
case, the dynamic library requirement is less significant, because the

// boundary of the block containing the last newline.
//
// Note that the GNU manual says that numeric values should be encoded in octal
// format. However, the GNU tar utility itself outputs these values in decimal.
// As such, this library treats values as being encoded in decimal.
func readGNUSparseMap1x0(r io.Reader) (sparseDatas, error) {
	var (
		cntNewline int64
		buf        bytes.Buffer

the compatibility guarantee ensures that a Go program that works with a
specific Go language version will continue to work with any subsequent version.
</p>

<p>
For instance, the ability to use the prefix <code>0b</code> for binary
integer literals was introduced with Go 1.13, indicated
by [<a href="#Go_1.13">Go 1.13</a>] in the section on
<a href="#Integer_literals">integer literals</a>.