diff --git a/pkg/build/build.go b/pkg/build/build.go
index f4edb55..4fcbe40 100644
--- a/pkg/build/build.go
+++ b/pkg/build/build.go
@@ -133,9 +133,9 @@ func (b *Build) determineOutputDir(outputDir string) (string, error) {
 	targetName := ""
 	for _, pkg := range b.Pkgs {
 		if pkg.Name == "main" {
-			if pkg.Target != ""{
+			if pkg.Target != "" {
 				targetName = filepath.Base(pkg.Target)
-			}else {
+			} else {
 				targetName = filepath.Base(pkg.Dir)
 			}
 			break
diff --git a/pkg/build/legacy_test.go b/pkg/build/legacy_test.go
index cb786ed..a6a01dd 100644
--- a/pkg/build/legacy_test.go
+++ b/pkg/build/legacy_test.go
@@ -46,6 +46,28 @@ func TestLegacyProjectCopyWithUnexistedDir(t *testing.T) {
 	assert.Equal(t, strings.Contains(output, "Failed to Copy"), true)
 }
 
+// copy goMod project without go.mod
+func TestGoModProjectCopyWithUnexistedModFile(t *testing.T) {
+	pkgs := make(map[string]*cover.Package)
+	pkgs["main"] = &cover.Package{
+		Module: &cover.ModulePublic{
+			Dir: "not exied, ia mas duser", // not real one, should fail copy
+		},
+		Dir:  "not exit, iasdfs",
+		Name: "main",
+	}
+	pkgs["another"] = &cover.Package{}
+	b := &Build{
+		TmpDir: "sdfsfev2234444", // not real one, should fail copy
+		Pkgs:   pkgs,
+		IsMod:  true,
+	}
+
+	output := captureOutput(b.cpLegacyProject)
+	assert.Equal(t, strings.Contains(output, "Failed to Copy the go mod file"), true)
+}
+
+// copy needed files to tmpDir
 func TestCopyDir(t *testing.T) {
 	wd, _ := os.Getwd()
 	pkg := &cover.Package{Dir: wd, Root: wd, GoFiles: []string{"build.go", "legacy.go"}, CgoFiles: []string{"run.go"}}
diff --git a/pkg/build/tmpfolder.go b/pkg/build/tmpfolder.go
index 95b9cf5..3c6a8f1 100644
--- a/pkg/build/tmpfolder.go
+++ b/pkg/build/tmpfolder.go
@@ -108,8 +108,6 @@ func (b *Build) mvProjectsToTmp() error {
 	} else if b.IsMod == false && b.Root == "" {
 		b.TmpWorkingDir = b.TmpDir
 		b.cpLegacyProject()
-	} else {
-		return fmt.Errorf("unknown project type: %w", ErrShouldNotReached)
 	}
 
 	log.Infof("New workingdir in tmp directory in: %v", b.TmpWorkingDir)
diff --git a/pkg/build/tmpfolder_test.go b/pkg/build/tmpfolder_test.go
index cf311e6..a837366 100644
--- a/pkg/build/tmpfolder_test.go
+++ b/pkg/build/tmpfolder_test.go
@@ -23,6 +23,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/qiniu/goc/pkg/cover"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -95,7 +96,7 @@ func TestLegacyProjectNotInGoPATH(t *testing.T) {
 	os.Setenv("GO111MODULE", "off")
 
 	b, _ := NewBuild("", []string{"."}, workingDir, "")
-	if !strings.Contains(b.NewGOPATH,b.OriGOPATH) {
+	if !strings.Contains(b.NewGOPATH, b.OriGOPATH) {
 		t.Fatalf("New GOPATH should be same with old GOPATH, for this kind of project. New: %v, old: %v", b.NewGOPATH, b.OriGOPATH)
 	}
 
@@ -105,13 +106,32 @@ func TestLegacyProjectNotInGoPATH(t *testing.T) {
 	}
 }
 
-// test traversePkgsList error case
-func TestTraversePkgsList(t *testing.T) {
+// test mvProjectsToTmp failed by traversePkgsList error
+func TestMvProjectsToTmpFailByTraversePkgsList(t *testing.T) {
 	b := &Build{
 		Pkgs: nil,
 	}
-	_, _, err := b.traversePkgsList()
-	assert.EqualError(t, err, ErrShouldNotReached.Error())
+	err := b.mvProjectsToTmp()
+	assert.Contains(t, err.Error(), ErrShouldNotReached.Error())
+}
+
+// test mvProjectsToTmp failed by getTmpwd error
+func TestMvProjectsToTmpFailByGetTmpwd(t *testing.T) {
+	pkgs := make(map[string]*cover.Package)
+	pkgs["main"] = &cover.Package{
+		Module: &cover.ModulePublic{
+			Dir:  "just for test",
+			Path: "just for test",
+		},
+		Dir:  "not exist",
+		Name: "main",
+	}
+	b := &Build{
+		Pkgs:       pkgs,
+		WorkingDir: "not exist",
+	}
+	err := b.mvProjectsToTmp()
+	assert.Contains(t, err.Error(), ErrGocShouldExecInProject.Error())
 }
 
 // test getTmpwd error case
@@ -148,3 +168,8 @@ func TestFindWhereToInstall(t *testing.T) {
 	expectedPlace := filepath.Join(os.Getenv("HOME"), "go", "bin")
 	assert.Equal(t, placeToInstall, expectedPlace)
 }
+
+func TestMvProjectsToTmp(t *testing.T) {
+	b := &Build{TmpDir: "/tmp/test"}
+	fmt.Println(b.MvProjectsToTmp())
+}