diff --git a/archiver_test.go b/archiver_test.go
index 2699593d..ea8b871d 100644
--- a/archiver_test.go
+++ b/archiver_test.go
@@ -3,7 +3,6 @@ package archiver
 import (
 	"bytes"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -323,7 +322,7 @@ func testArchiveUnarchive(t *testing.T, au archiverUnarchiver) {
 
 	// Test extracting archive
 	dest := filepath.Join(tmp, "extraction_test_"+auStr)
-	os.Mkdir(dest, 0755)
+	_ = os.Mkdir(dest, 0755)
 	err = au.Unarchive(outfile, dest)
 	if err != nil {
 		t.Fatalf("[%s] extracting archive [%s -> %s]: didn't expect an error, but got: %v", auStr, outfile, dest, err)
@@ -333,6 +332,7 @@ func testArchiveUnarchive(t *testing.T, au archiverUnarchiver) {
 	symmetricTest(t, auStr, dest, true, true)
 }
 
+/*
 // testMatching tests that au can match the format of archiveFile.
 func testMatching(t *testing.T, au archiverUnarchiver, archiveFile string) {
 	m, ok := au.(Matcher)
@@ -358,12 +358,13 @@ func testMatching(t *testing.T, au archiverUnarchiver, archiveFile string) {
 		t.Fatalf("%s (%T): format should have matched, but didn't", m, m)
 	}
 }
+*/
 
 // symmetricTest compares the contents of a destination directory to the contents
 // of the test corpus and tests that they are equal.
 func symmetricTest(t *testing.T, formatName, dest string, testSymlinks, testModes bool) {
 	var expectedFileCount int
-	filepath.Walk("testdata/corpus", func(fpath string, info os.FileInfo, err error) error {
+	_ = filepath.Walk("testdata/corpus", func(fpath string, info os.FileInfo, err error) error {
 		if testSymlinks || (info.Mode()&os.ModeSymlink) == 0 {
 			expectedFileCount++
 		}
@@ -373,7 +374,7 @@ func symmetricTest(t *testing.T, formatName, dest string, testSymlinks, testMode
 	// If outputs equals inputs, we're good; traverse output files
 	// and compare file names, file contents, and file count.
 	var actualFileCount int
-	filepath.Walk(dest, func(fpath string, info os.FileInfo, err error) error {
+	_ = filepath.Walk(dest, func(fpath string, info os.FileInfo, _ error) error {
 		if fpath == dest {
 			return nil
 		}
diff --git a/cmd/arc/main.go b/cmd/arc/main.go
index dd86bd3e..140255b1 100644
--- a/cmd/arc/main.go
+++ b/cmd/arc/main.go
@@ -219,7 +219,7 @@ func getFormat(subcommand string) (interface{}, error) {
 		v.ContinueOnError = continueOnError
 		v.Password = os.Getenv("ARCHIVE_PASSWORD")
 	case *archiver.Tar:
-		v = mytar
+		f = mytar
 	case *archiver.TarBrotli:
 		v.Tar = mytar
 		v.Quality = compressionLevel
diff --git a/rar.go b/rar.go
index 84eabda8..8fdf223c 100644
--- a/rar.go
+++ b/rar.go
@@ -363,7 +363,9 @@ func (*Rar) Match(file io.ReadSeeker) (bool, error) {
 	if err != nil {
 		return false, err
 	}
-	defer file.Seek(currentPos, io.SeekStart)
+	defer func() {
+		_, _ = file.Seek(currentPos, io.SeekStart)
+	}()
 
 	buf := make([]byte, 8)
 	if n, err := file.Read(buf); err != nil || n < 8 {
diff --git a/sz.go b/sz.go
index 39c5865e..02009b52 100644
--- a/sz.go
+++ b/sz.go
@@ -13,7 +13,7 @@ type Snappy struct{}
 
 // Compress reads in, compresses it, and writes it to out.
 func (s *Snappy) Compress(in io.Reader, out io.Writer) error {
-	w := snappy.NewWriter(out)
+	w := snappy.NewBufferedWriter(out)
 	defer w.Close()
 	_, err := io.Copy(w, in)
 	return err
diff --git a/tar.go b/tar.go
index 6dda50a0..dbac6920 100644
--- a/tar.go
+++ b/tar.go
@@ -546,7 +546,9 @@ func (*Tar) Match(file io.ReadSeeker) (bool, error) {
 	if err != nil {
 		return false, err
 	}
-	defer file.Seek(currentPos, io.SeekStart)
+	defer func() {
+		_, _ = file.Seek(currentPos, io.SeekStart)
+	}()
 
 	buf := make([]byte, tarBlockSize)
 	if _, err = io.ReadFull(file, buf); err != nil {
diff --git a/tarsz.go b/tarsz.go
index 0569e664..ee3808e6 100644
--- a/tarsz.go
+++ b/tarsz.go
@@ -77,7 +77,7 @@ func (tsz *TarSz) Extract(source, target, destination string) error {
 func (tsz *TarSz) wrapWriter() {
 	var sw *snappy.Writer
 	tsz.Tar.writerWrapFn = func(w io.Writer) (io.Writer, error) {
-		sw = snappy.NewWriter(w)
+		sw = snappy.NewBufferedWriter(w)
 		return sw, nil
 	}
 	tsz.Tar.cleanupWrapFn = func() {
diff --git a/zip.go b/zip.go
index 416fdac9..0fa08b7d 100644
--- a/zip.go
+++ b/zip.go
@@ -76,11 +76,11 @@ type Zip struct {
 	ContinueOnError bool
 
 	// Compression algorithm
-	FileMethod     ZipCompressionMethod
-	zw             *zip.Writer
-	zr             *zip.Reader
-	ridx           int
-	decinitialized bool
+	FileMethod ZipCompressionMethod
+	zw         *zip.Writer
+	zr         *zip.Reader
+	ridx       int
+	//decinitialized bool
 }
 
 // CheckExt ensures the file extension matches the format.
@@ -596,7 +596,9 @@ func (*Zip) Match(file io.ReadSeeker) (bool, error) {
 	if err != nil {
 		return false, err
 	}
-	defer file.Seek(currentPos, io.SeekStart)
+	defer func() {
+		_, _ = file.Seek(currentPos, io.SeekStart)
+	}()
 
 	buf := make([]byte, 4)
 	if n, err := file.Read(buf); err != nil || n < 4 {