diff --git a/chglog_test.go b/chglog_test.go
index 586460ac..1828fa89 100644
--- a/chglog_test.go
+++ b/chglog_test.go
@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	gitcmd "github.com/tsuyoshiwada/go-gitcmd"
@@ -30,6 +31,9 @@ func setup(dir string, setupRepo func(gitcmd.Client)) {
 	os.MkdirAll(testDir, os.ModePerm)
 	os.Chdir(testDir)
 
+	loc, _ := time.LoadLocation("UTC")
+	time.Local = loc
+
 	git := gitcmd.New(nil)
 	git.Exec("init")
 	git.Exec("config", "user.name", "test_user")
@@ -91,9 +95,63 @@ func TestGeneratorNotFoundCommits(t *testing.T) {
 		},
 	})
 
+	buf := &bytes.Buffer{}
+	err := gen.Generate(buf, "foo")
+	assert.Error(err)
+	assert.Equal("", buf.String())
+}
+
+func TestGeneratorNotFoundCommitsOne(t *testing.T) {
+	assert := assert.New(t)
+	testName := "not_found"
+
+	setup(testName, func(git gitcmd.Client) {
+		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:00:00 2018 +0000", "-m", "chore(*): First commit")
+	})
+
+	gen := NewGenerator(&Config{
+		Bin:        "git",
+		WorkingDir: filepath.Join(testRepoRoot, testName),
+		Template:   filepath.Join(cwd, "testdata", testName+".md"),
+		Info: &Info{
+			RepositoryURL: "https://github.com/git-chglog/git-chglog",
+		},
+		Options: &Options{
+			CommitFilters:        map[string][]string{},
+			CommitSortBy:         "Scope",
+			CommitGroupBy:        "Type",
+			CommitGroupSortBy:    "Title",
+			CommitGroupTitleMaps: map[string]string{},
+			HeaderPattern:        "^(\\w*)(?:\\(([\\w\\$\\.\\-\\*\\s]*)\\))?\\:\\s(.*)$",
+			HeaderPatternMaps: []string{
+				"Type",
+				"Scope",
+				"Subject",
+			},
+			IssuePrefix: []string{
+				"#",
+				"gh-",
+			},
+			RefActions:   []string{},
+			MergePattern: "^Merge pull request #(\\d+) from (.*)$",
+			MergePatternMaps: []string{
+				"Ref",
+				"Source",
+			},
+			RevertPattern: "^Revert \"([\\s\\S]*)\"$",
+			RevertPatternMaps: []string{
+				"Header",
+			},
+			NoteKeywords: []string{
+				"BREAKING CHANGE",
+			},
+		},
+	})
+
 	buf := &bytes.Buffer{}
 	err := gen.Generate(buf, "foo")
 	assert.Contains(err.Error(), "\"foo\" was not found")
+	assert.Error(err)
 	assert.Equal("", buf.String())
 }
 
@@ -102,23 +160,23 @@ func TestGeneratorWithTypeScopeSubject(t *testing.T) {
 	testName := "type_scope_subject"
 
 	setup(testName, func(git gitcmd.Client) {
-		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:00:00 2018 +0900", "-m", "chore(*): First commit")
-		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:01:00 2018 +0900", "-m", "feat(core): Add foo bar")
-		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:02:00 2018 +0900", "-m", "docs(readme): Update usage #123")
+		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:00:00 2018 +0000", "-m", "chore(*): First commit")
+		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:01:00 2018 +0000", "-m", "feat(core): Add foo bar")
+		git.Exec("commit", "--allow-empty", "--date", "Mon Jan 1 00:02:00 2018 +0000", "-m", "docs(readme): Update usage #123")
 
 		git.Exec("tag", "1.0.0")
-		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:00:00 2018 +0900", "-m", "feat(parser): New some super options #333")
-		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:01:00 2018 +0900", "-m", "Merge pull request #999 from tsuyoshiwada/patch-1")
-		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:02:00 2018 +0900", "-m", "Merge pull request #1000 from tsuyoshiwada/patch-1")
-		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:03:00 2018 +0900", "-m", "Revert \"feat(core): Add foo bar @mention and issue #987\"")
+		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:00:00 2018 +0000", "-m", "feat(parser): New some super options #333")
+		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:01:00 2018 +0000", "-m", "Merge pull request #999 from tsuyoshiwada/patch-1")
+		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:02:00 2018 +0000", "-m", "Merge pull request #1000 from tsuyoshiwada/patch-1")
+		git.Exec("commit", "--allow-empty", "--date", "Tue Jan 2 00:03:00 2018 +0000", "-m", "Revert \"feat(core): Add foo bar @mention and issue #987\"")
 
 		git.Exec("tag", "1.1.0")
-		git.Exec("commit", "--allow-empty", "--date", "Wed Jan 3 00:00:00 2018 +0900", "-m", "feat(context): Online breaking change\n\nBREAKING CHANGE: Online breaking change message.")
-		git.Exec("commit", "--allow-empty", "--date", "Wed Jan 3 00:01:00 2018 +0900", "-m", "feat(router): Muliple breaking change\n\nThis is body,\n\nBREAKING CHANGE:\nMultiple\nbreaking\nchange message.")
+		git.Exec("commit", "--allow-empty", "--date", "Wed Jan 3 00:00:00 2018 +0000", "-m", "feat(context): Online breaking change\n\nBREAKING CHANGE: Online breaking change message.")
+		git.Exec("commit", "--allow-empty", "--date", "Wed Jan 3 00:01:00 2018 +0000", "-m", "feat(router): Muliple breaking change\n\nThis is body,\n\nBREAKING CHANGE:\nMultiple\nbreaking\nchange message.")
 
 		git.Exec("tag", "2.0.0-beta.0")
-		git.Exec("commit", "--allow-empty", "--date", "Thu Jan 4 00:00:00 2018 +0900", "-m", "refactor(context): gofmt")
-		git.Exec("commit", "--allow-empty", "--date", "Thu Jan 4 00:01:00 2018 +0900", "-m", "fix(core): Fix commit\n\nThis is body message.")
+		git.Exec("commit", "--allow-empty", "--date", "Thu Jan 4 00:00:00 2018 +0000", "-m", "refactor(context): gofmt")
+		git.Exec("commit", "--allow-empty", "--date", "Thu Jan 4 00:01:00 2018 +0000", "-m", "fix(core): Fix commit\n\nThis is body message.")
 	})
 
 	gen := NewGenerator(&Config{
diff --git a/scripts/release.sh b/scripts/release.sh
index 6431dd21..dc2b3ddc 100755
--- a/scripts/release.sh
+++ b/scripts/release.sh
@@ -2,7 +2,7 @@
 
 REPO_ROOT=$(git rev-parse --show-toplevel)
 
-if [[ "$TRAVIS_BRANCH" == "master" ]]; then
+if [[ "$TRAVIS_BRANCH" == "master" ]] && [[ "$TRAVIS_TAG" != "" ]] && [[ "$TRAVIS_PULL_REQUEST" != "" ]]; then
   echo "Start release ..."
   gox -os="darwin linux windows" -arch="amd64 386" -output="$REPO_ROOT/dist/{{.Dir}}_{{.OS}}_{{.Arch}}" ./cmd/git-chglog
   ghr --username git-chglog --token $GITHUB_TOKEN --replace `grep 'Version =' ./cmd/git-chglog/version.go | sed -E 's/.*"(.+)"$$/\1/'` dist/
diff --git a/tag_reader.go b/tag_reader.go
index 7c8aa622..5cb35840 100644
--- a/tag_reader.go
+++ b/tag_reader.go
@@ -1,6 +1,7 @@
 package chglog
 
 import (
+	"fmt"
 	"regexp"
 	"strconv"
 	"strings"
@@ -33,7 +34,7 @@ func (r *tagReader) ReadAll() ([]*Tag, error) {
 	tags := []*Tag{}
 
 	if err != nil {
-		return tags, err
+		return tags, fmt.Errorf("failed to get git-tag: %s", err.Error())
 	}
 
 	lines := strings.Split(out, "\n")