chore: change LinkTargetNotFoundError impl

internal/deb/extract.go

@@ -4,6 +4,7 @@ import (
 	"archive/tar"
 	"bytes"
 	"compress/gzip"
+	"errors"
 	"fmt"
 	"io"
 	"io/fs"
@@ -277,7 +278,7 @@ func extractData(pkgReader io.ReadSeeker, options *ExtractOptions) error {
 			err := options.Create(extractInfos, createOptions)
 			if err != nil {
 				// Handle the hard link where its counterpart is not extracted
-				if tarHeader.Typeflag == tar.TypeLink && strings.HasPrefix(err.Error(), "link target does not exist") {
+				if tarHeader.Typeflag == tar.TypeLink && errors.Is(err, fsutil.LinkTargetNotExistError) {
 					basePath := sanitizePath(tarHeader.Linkname)
 					pendingHardlinks[basePath] = append(pendingHardlinks[basePath],
 						PendingHardlink{

internal/fsutil/create.go

@@ -159,11 +159,13 @@ func createSymlink(o *CreateOptions) error {
 	return os.Symlink(o.Link, o.Path)
 }
 
+var LinkTargetNotExistError = fmt.Errorf("link target does not exist")
+
 func createHardLink(o *CreateOptions) error {
 	debugf("Creating hard link: %s => %s", o.Path, o.Link)
 	linkInfo, err := os.Lstat(o.Link)
 	if err != nil && os.IsNotExist(err) {
-		return &LinkTargetNotExistError{Link: o.Link}
+		return LinkTargetNotExistError
 	} else if err != nil {
 		return err
 	}
@@ -223,11 +225,3 @@ func (rp *writerProxy) Close() error {
 	rp.entry.Size = rp.size
 	return rp.inner.Close()
 }
-
-type LinkTargetNotExistError struct {
-	Link string
-}
-
-func (e *LinkTargetNotExistError) Error() string {
-	return fmt.Sprintf("link target does not exist: %s", e.Link)
-}

internal/fsutil/create_test.go

@@ -130,7 +130,7 @@ var createTests = []createTest{{
 	hackopt: func(c *C, targetDir string, options *fsutil.CreateOptions) {
 		options.Link = filepath.Join(targetDir, options.Link)
 	},
-	error: `link target does not exist: \/[^ ]*\/missing-file`,
+	error: `link target does not exist`,
 }, {
 	summary: "Re-creating a duplicated hard link keeps the original link",
 	options: fsutil.CreateOptions{