diff --git a/go.mod b/go.mod
index ab03afb..9a63ef6 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,6 @@ module github.com/goplus/mod
 go 1.16
 
 require (
-	github.com/qiniu/x v1.11.8
+	github.com/qiniu/x v1.11.9
 	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4
 )
diff --git a/go.sum b/go.sum
index 523a8ff..c37a533 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-github.com/qiniu/x v1.11.8 h1:Jol2Nm/wNIUSk+oxebNZbYPZ1gW/UI4C6FsN5xZzcQQ=
-github.com/qiniu/x v1.11.8/go.mod h1:03Ni9tj+N2h2aKnAz+6N0Xfl8FwMEDRC2PAlxekASDs=
+github.com/qiniu/x v1.11.9 h1:IfQNdeNcK43Q1+b/LdrcqmWjlhxq051YVBnua8J2qN8=
+github.com/qiniu/x v1.11.9/go.mod h1:03Ni9tj+N2h2aKnAz+6N0Xfl8FwMEDRC2PAlxekASDs=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
diff --git a/modfile/gop_test.go b/modfile/gop_test.go
index 12dc526..61afc74 100644
--- a/modfile/gop_test.go
+++ b/modfile/gop_test.go
@@ -20,6 +20,7 @@ import (
 	"path/filepath"
 	"testing"
 
+	"github.com/qiniu/x/errors"
 	"golang.org/x/mod/modfile"
 )
 
@@ -224,7 +225,7 @@ register -
 classfile .gmx .spx github.com/goplus/spx math
 classfile .gmx .spx github.com/goplus/spx math
 `)
-	doTestParseErr(t, `gop.mod:2: usage: classfile projExt workExt [classFilePkgPath ...]`, `
+	doTestParseErr(t, `gop.mod:2: usage: classfile projExt workExt classFilePkgPath ...`, `
 classfile .gmx .spx
 `)
 	doTestParseErr(t, `gop.mod:2: ext . invalid: invalid ext format`, `
@@ -247,12 +248,12 @@ go 1.x
 func doTestParseErr(t *testing.T, errMsg string, gopmod string) {
 	t.Run(errMsg, func(t *testing.T) {
 		_, err := Parse("gop.mod", []byte(gopmod), nil)
-		if err == nil {
+		if err == nil || err.Error() == "" {
 			t.Fatal("Parse: no error?")
 			return
 		}
-		if err.Error() != errMsg {
-			t.Error("Parse got:", err, "\nExpected:", errMsg)
+		if errRet := errors.Summary(err); errRet != errMsg {
+			t.Error("Parse got:", errRet, "\nExpected:", errMsg)
 		}
 	})
 }
diff --git a/modfile/rule.go b/modfile/rule.go
index f03ddbd..a0b591d 100644
--- a/modfile/rule.go
+++ b/modfile/rule.go
@@ -132,7 +132,7 @@ func parseToFile(file string, data []byte, fix VersionFixer, strict bool) (parse
 
 func (f *File) parseVerb(errs *ErrorList, verb string, line *Line, args []string, strict bool) {
 	wrapModPathError := func(modPath string, err error) {
-		*errs = append(*errs, Error{
+		errs.Add(&Error{
 			Filename: f.Syntax.Name,
 			Pos:      line.Start,
 			ModPath:  modPath,
@@ -141,7 +141,7 @@ func (f *File) parseVerb(errs *ErrorList, verb string, line *Line, args []string
 		})
 	}
 	wrapError1 := func(err error) {
-		*errs = append(*errs, Error{
+		errs.Add(&Error{
 			Filename: f.Syntax.Name,
 			Pos:      line.Start,
 			Err:      err,
@@ -403,8 +403,22 @@ func (e *InvalidExtError) Error() string {
 
 func (e *InvalidExtError) Unwrap() error { return e.Err }
 
-type ErrorList = modfile.ErrorList
-type Error = modfile.Error
+type ErrorList = errors.List
+type Error modfile.Error
+
+func (p *Error) Error() string {
+	return (*modfile.Error)(p).Error()
+}
+
+func (p *Error) Unwrap() error {
+	return p.Err
+}
+
+func (p *Error) Summary() string {
+	cpy := *(*modfile.Error)(p)
+	cpy.Err = errors.New(errors.Summary(p.Unwrap()))
+	return cpy.Error()
+}
 
 // -----------------------------------------------------------------------------