diff --git a/.travis.yml b/.travis.yml
index c6d4263b..75ab7c47 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,12 +3,12 @@ language: go
 matrix:
   include:
     - os: linux
-      go: 1.9.1
+      go: 1.9
     - os: linux
       go: tip
     - os: osx
       osx_image: xcode8.3
-      go: 1.9.1
+      go: 1.9
     - os: osx
       osx_image: xcode8.3
       go: tip
diff --git a/README.md b/README.md
index 198fc135..53301ab4 100644
--- a/README.md
+++ b/README.md
@@ -125,7 +125,9 @@ Or download binaries from [GitHub releases](https://github.com/vim-volt/volt/rel
 
 ## Build environment
 
-* Go 1.9.1 or higher **with [the patch for os.RemoveAll()](https://go-review.googlesource.com/c/go/+/62970) ([#1](https://github.com/vim-volt/go-volt/issues/1))**
+* Go 1.9 or higher
+  * If you are on WSL (Windows Subsystem Linux), note that you need **[the patch for os.RemoveAll()](https://go-review.googlesource.com/c/go/+/62970) ([#1](https://github.com/vim-volt/go-volt/issues/1))**
+  * But it's a hassle, you can just download linux-386/amd64 binaries from [GitHub releases](https://github.com/vim-volt/volt/releases) :)
 
 ## Self upgrade
 
diff --git a/cmd/build.go b/cmd/build.go
index 700d176b..7831e3ef 100644
--- a/cmd/build.go
+++ b/cmd/build.go
@@ -26,17 +26,18 @@ import (
 	"gopkg.in/src-d/go-git.v4/plumbing/object"
 )
 
-type buildFlagsType struct {
+var BuildModeInvalidType = os.ModeSymlink | os.ModeNamedPipe | os.ModeSocket | os.ModeDevice
+
+func init() {
+	cmdMap["build"] = &buildCmd{}
+}
+
+type buildCmd struct {
 	helped bool
 	full   bool
 }
 
-var buildFlags buildFlagsType
-
-var BuildModeInvalidType = os.ModeSymlink | os.ModeNamedPipe | os.ModeSocket | os.ModeDevice
-var ErrBuildModeType = "does not allow symlink, named pipe, socket, device"
-
-func init() {
+func (cmd *buildCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -62,22 +63,17 @@ Description
 		fmt.Println("Options")
 		fs.PrintDefaults()
 		fmt.Println()
-		buildFlags.helped = true
+		cmd.helped = true
 	}
-	fs.BoolVar(&buildFlags.full, "full", false, "full build")
-
-	cmdFlagSet["build"] = fs
+	fs.BoolVar(&cmd.full, "full", false, "full build")
+	return fs
 }
 
-type buildCmd struct{}
-
-func Build(args []string) int {
-	cmd := buildCmd{}
-
+func (cmd *buildCmd) Run(args []string) int {
 	// Parse args
-	fs := cmdFlagSet["build"]
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if buildFlags.helped {
+	if cmd.helped {
 		return 0
 	}
 
@@ -89,7 +85,7 @@ func Build(args []string) int {
 	}
 	defer transaction.Remove()
 
-	err = cmd.doBuild(buildFlags.full)
+	err = cmd.doBuild(cmd.full)
 	if err != nil {
 		logger.Error("Failed to build:", err.Error())
 		return 12
@@ -799,12 +795,8 @@ func (cmd *buildCmd) updateNonBareGitRepos(r *git.Repository, src, dst string, r
 			continue
 		}
 		if file.Mode()&BuildModeInvalidType != 0 {
-			abspath := filepath.Join(src, file.Name())
-			done <- actionReposResult{
-				err:   errors.New(ErrBuildModeType + ": " + abspath),
-				repos: repos,
-			}
-			return
+			// Currenly skip the invalid files...
+			continue
 		}
 		if !created[dst] {
 			os.MkdirAll(dst, 0755)
diff --git a/cmd/cmd.go b/cmd/cmd.go
new file mode 100644
index 00000000..701c2652
--- /dev/null
+++ b/cmd/cmd.go
@@ -0,0 +1,22 @@
+package cmd
+
+import (
+	"flag"
+
+	"github.com/vim-volt/volt/logger"
+)
+
+var cmdMap = make(map[string]Cmd)
+
+type Cmd interface {
+	Run(args []string) int
+	FlagSet() *flag.FlagSet
+}
+
+func Run(subCmd string, args []string) int {
+	if self, exists := cmdMap[subCmd]; exists {
+		return self.Run(args)
+	}
+	logger.Error("Unknown command '" + subCmd + "'")
+	return 3
+}
diff --git a/cmd/disable.go b/cmd/disable.go
index a363ff3f..6072bfe1 100644
--- a/cmd/disable.go
+++ b/cmd/disable.go
@@ -10,13 +10,15 @@ import (
 	"github.com/vim-volt/volt/pathutil"
 )
 
-type disableFlagsType struct {
-	helped bool
+func init() {
+	cmdMap["disable"] = &disableCmd{}
 }
 
-var disableFlags disableFlagsType
+type disableCmd struct {
+	helped bool
+}
 
-func init() {
+func (cmd *disableCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -33,17 +35,12 @@ Description
 		//fmt.Println("Options")
 		//fs.PrintDefaults()
 		fmt.Println()
-		disableFlags.helped = true
+		cmd.helped = true
 	}
-
-	cmdFlagSet["disable"] = fs
+	return fs
 }
 
-type disableCmd struct{}
-
-func Disable(args []string) int {
-	cmd := disableCmd{}
-
+func (cmd *disableCmd) Run(args []string) int {
 	reposPathList, err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
 		return 0
@@ -66,10 +63,10 @@ func Disable(args []string) int {
 	return 0
 }
 
-func (*disableCmd) parseArgs(args []string) ([]string, error) {
-	fs := cmdFlagSet["disable"]
+func (cmd *disableCmd) parseArgs(args []string) ([]string, error) {
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if disableFlags.helped {
+	if cmd.helped {
 		return nil, ErrShowedHelp
 	}
 
diff --git a/cmd/enable.go b/cmd/enable.go
index a8f8c78e..a52f04d3 100644
--- a/cmd/enable.go
+++ b/cmd/enable.go
@@ -10,13 +10,15 @@ import (
 	"github.com/vim-volt/volt/pathutil"
 )
 
-type enableFlagsType struct {
-	helped bool
+func init() {
+	cmdMap["enable"] = &enableCmd{}
 }
 
-var enableFlags enableFlagsType
+type enableCmd struct {
+	helped bool
+}
 
-func init() {
+func (cmd *enableCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -33,17 +35,12 @@ Description
 		//fmt.Println("Options")
 		//fs.PrintDefaults()
 		fmt.Println()
-		enableFlags.helped = true
+		cmd.helped = true
 	}
-
-	cmdFlagSet["enable"] = fs
+	return fs
 }
 
-type enableCmd struct{}
-
-func Enable(args []string) int {
-	cmd := enableCmd{}
-
+func (cmd *enableCmd) Run(args []string) int {
 	reposPathList, err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
 		return 0
@@ -66,10 +63,10 @@ func Enable(args []string) int {
 	return 0
 }
 
-func (*enableCmd) parseArgs(args []string) ([]string, error) {
-	fs := cmdFlagSet["enable"]
+func (cmd *enableCmd) parseArgs(args []string) ([]string, error) {
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if enableFlags.helped {
+	if cmd.helped {
 		return nil, ErrShowedHelp
 	}
 
diff --git a/cmd/get.go b/cmd/get.go
index a9944e76..1a8f538f 100644
--- a/cmd/get.go
+++ b/cmd/get.go
@@ -22,16 +22,18 @@ import (
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/sideband"
 )
 
-type getFlagsType struct {
+func init() {
+	cmdMap["get"] = &getCmd{}
+}
+
+type getCmd struct {
 	helped   bool
 	lockJSON bool
 	upgrade  bool
 	verbose  bool
 }
 
-var getFlags getFlagsType
-
-func init() {
+func (cmd *getCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -102,22 +104,17 @@ Repository path
 Options`)
 		fs.PrintDefaults()
 		fmt.Println()
-		getFlags.helped = true
+		cmd.helped = true
 	}
-	fs.BoolVar(&getFlags.lockJSON, "l", false, "use all installed repositories as targets")
-	fs.BoolVar(&getFlags.upgrade, "u", false, "upgrade repositories")
-	fs.BoolVar(&getFlags.verbose, "v", false, "output more verbosely")
-
-	cmdFlagSet["get"] = fs
+	fs.BoolVar(&cmd.lockJSON, "l", false, "use all installed repositories as targets")
+	fs.BoolVar(&cmd.upgrade, "u", false, "upgrade repositories")
+	fs.BoolVar(&cmd.verbose, "v", false, "output more verbosely")
+	return fs
 }
 
-type getCmd struct{}
-
-func Get(args []string) int {
-	cmd := getCmd{}
-
+func (cmd *getCmd) Run(args []string) int {
 	// Parse args
-	args, flags, err := cmd.parseArgs(args)
+	args, err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
 		return 0
 	}
@@ -133,7 +130,7 @@ func Get(args []string) int {
 		return 11
 	}
 
-	reposPathList, err := cmd.getReposPathList(flags, args, lockJSON)
+	reposPathList, err := cmd.getReposPathList(args, lockJSON)
 	if err != nil {
 		logger.Error("Could not get repos list: " + err.Error())
 		return 12
@@ -143,7 +140,7 @@ func Get(args []string) int {
 		return 13
 	}
 
-	err = cmd.doGet(reposPathList, flags, lockJSON)
+	err = cmd.doGet(reposPathList, lockJSON)
 	if err != nil {
 		logger.Error(err.Error())
 		return 20
@@ -152,24 +149,24 @@ func Get(args []string) int {
 	return 0
 }
 
-func (*getCmd) parseArgs(args []string) ([]string, *getFlagsType, error) {
-	fs := cmdFlagSet["get"]
+func (cmd *getCmd) parseArgs(args []string) ([]string, error) {
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if getFlags.helped {
-		return nil, nil, ErrShowedHelp
+	if cmd.helped {
+		return nil, ErrShowedHelp
 	}
 
-	if !getFlags.lockJSON && len(fs.Args()) == 0 {
+	if !cmd.lockJSON && len(fs.Args()) == 0 {
 		fs.Usage()
-		return nil, nil, errors.New("repository was not given")
+		return nil, errors.New("repository was not given")
 	}
 
-	return fs.Args(), &getFlags, nil
+	return fs.Args(), nil
 }
 
-func (*getCmd) getReposPathList(flags *getFlagsType, args []string, lockJSON *lockjson.LockJSON) ([]string, error) {
+func (cmd *getCmd) getReposPathList(args []string, lockJSON *lockjson.LockJSON) ([]string, error) {
 	reposPathList := make([]string, 0, 32)
-	if flags.lockJSON {
+	if cmd.lockJSON {
 		for _, repos := range lockJSON.Repos {
 			reposPathList = append(reposPathList, repos.Path)
 		}
@@ -185,7 +182,7 @@ func (*getCmd) getReposPathList(flags *getFlagsType, args []string, lockJSON *lo
 	return reposPathList, nil
 }
 
-func (cmd *getCmd) doGet(reposPathList []string, flags *getFlagsType, lockJSON *lockjson.LockJSON) error {
+func (cmd *getCmd) doGet(reposPathList []string, lockJSON *lockjson.LockJSON) error {
 	// Find matching profile
 	profile, err := lockJSON.Profiles.FindByName(lockJSON.CurrentProfileName)
 	if err != nil {
@@ -211,7 +208,7 @@ func (cmd *getCmd) doGet(reposPathList []string, flags *getFlagsType, lockJSON *
 			repos = nil
 		}
 		if repos == nil || repos.Type == lockjson.ReposGitType {
-			go cmd.getParallel(reposPath, repos, flags, done)
+			go cmd.getParallel(reposPath, repos, done)
 			getCount++
 		}
 	}
@@ -308,11 +305,11 @@ const (
 )
 
 // This function is executed in goroutine of each plugin
-func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *getFlagsType, done chan getParallelResult) {
+func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, done chan getParallelResult) {
 
 	// true:upgrade, false:install
 	fullReposPath := pathutil.FullReposPathOf(reposPath)
-	doUpgrade := flags.upgrade && pathutil.Exists(fullReposPath)
+	doUpgrade := cmd.upgrade && pathutil.Exists(fullReposPath)
 
 	var fromHash string
 	var err error
@@ -321,7 +318,7 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 		fromHash, err = getReposHEAD(reposPath)
 		if err != nil {
 			result := errors.New("failed to get HEAD commit hash: " + err.Error())
-			if flags.verbose {
+			if cmd.verbose {
 				logger.Info("Rollbacking " + fullReposPath + " ...")
 			} else {
 				logger.Debug("Rollbacking " + fullReposPath + " ...")
@@ -343,7 +340,7 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 	var upgraded bool
 
 	if doUpgrade {
-		// when flags.upgrade is true, repos must not be nil.
+		// when cmd.upgrade is true, repos must not be nil.
 		if repos == nil {
 			msg := "-u was specified but repos == nil"
 			done <- getParallelResult{
@@ -353,15 +350,15 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 			}
 		}
 		// Upgrade plugin
-		if flags.verbose {
+		if cmd.verbose {
 			logger.Info("Upgrading " + reposPath + " ...")
 		} else {
 			logger.Debug("Upgrading " + reposPath + " ...")
 		}
-		err := cmd.upgradePlugin(reposPath, flags)
+		err := cmd.upgradePlugin(reposPath)
 		if err != git.NoErrAlreadyUpToDate && err != nil {
 			result := errors.New("failed to upgrade plugin: " + err.Error())
-			if flags.verbose {
+			if cmd.verbose {
 				logger.Info("Rollbacking " + fullReposPath + " ...")
 			} else {
 				logger.Debug("Rollbacking " + fullReposPath + " ...")
@@ -384,16 +381,16 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 		}
 	} else if !pathutil.Exists(fullReposPath) {
 		// Install plugin
-		if flags.verbose {
+		if cmd.verbose {
 			logger.Info("Installing " + reposPath + " ...")
 		} else {
 			logger.Debug("Installing " + reposPath + " ...")
 		}
-		err := cmd.installPlugin(reposPath, flags)
+		err := cmd.installPlugin(reposPath)
 		// if err == errRepoExists, silently skip
 		if err != nil && err != errRepoExists {
 			result := errors.New("failed to install plugin: " + err.Error())
-			if flags.verbose {
+			if cmd.verbose {
 				logger.Info("Rollbacking " + fullReposPath + " ...")
 			} else {
 				logger.Debug("Rollbacking " + fullReposPath + " ...")
@@ -413,7 +410,7 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 			status = fmt.Sprintf(fmtAlreadyExists, statusPrefixNoChange, reposPath)
 		} else {
 			// Install plugconf
-			if flags.verbose {
+			if cmd.verbose {
 				logger.Info("Installing plugconf " + reposPath + " ...")
 			} else {
 				logger.Debug("Installing plugconf " + reposPath + " ...")
@@ -421,7 +418,7 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 			err = cmd.installPlugconf(reposPath)
 			if err != nil {
 				result := errors.New("failed to install plugconf: " + err.Error())
-				if flags.verbose {
+				if cmd.verbose {
 					logger.Info("Rollbacking " + fullReposPath + " ...")
 				} else {
 					logger.Debug("Rollbacking " + fullReposPath + " ...")
@@ -448,7 +445,7 @@ func (cmd *getCmd) getParallel(reposPath string, repos *lockjson.Repos, flags *g
 		toHash, err = getReposHEAD(reposPath)
 		if err != nil {
 			result := errors.New("failed to get HEAD commit hash: " + err.Error())
-			if flags.verbose {
+			if cmd.verbose {
 				logger.Info("Rollbacking " + fullReposPath + " ...")
 			} else {
 				logger.Debug("Rollbacking " + fullReposPath + " ...")
@@ -500,11 +497,11 @@ func (*getCmd) rollbackRepos(fullReposPath string) error {
 	return nil
 }
 
-func (cmd *getCmd) upgradePlugin(reposPath string, flags *getFlagsType) error {
+func (cmd *getCmd) upgradePlugin(reposPath string) error {
 	fullpath := pathutil.FullReposPathOf(reposPath)
 
 	var progress sideband.Progress = nil
-	// if flags.verbose {
+	// if cmd.verbose {
 	// 	progress = os.Stdout
 	// }
 
@@ -537,14 +534,14 @@ func (cmd *getCmd) upgradePlugin(reposPath string, flags *getFlagsType) error {
 
 var errRepoExists = errors.New("repository exists")
 
-func (cmd *getCmd) installPlugin(reposPath string, flags *getFlagsType) error {
+func (cmd *getCmd) installPlugin(reposPath string) error {
 	fullpath := pathutil.FullReposPathOf(reposPath)
 	if pathutil.Exists(fullpath) {
 		return errRepoExists
 	}
 
 	var progress sideband.Progress = nil
-	// if flags.verbose {
+	// if cmd.verbose {
 	// 	progress = os.Stdout
 	// }
 
diff --git a/cmd/help.go b/cmd/help.go
index 242bb7b8..6e7eae58 100644
--- a/cmd/help.go
+++ b/cmd/help.go
@@ -4,47 +4,36 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"os"
 
 	"github.com/vim-volt/volt/logger"
 )
 
-var cmdFlagSet = make(map[string]*flag.FlagSet)
-
 var ErrShowedHelp = errors.New("already showed help")
 
-func Help(args []string) int {
-	if len(args) == 0 {
-		showHelp()
-		return 0
-	}
-	if args[0] == "help" { // "volt help help"
-		fmt.Println("E478: Don't panic!")
-		return 0
-	}
-
-	if fs, exists := cmdFlagSet[args[0]]; exists {
-		fs.Usage()
-		return 0
-	} else {
-		logger.Errorf("Unknown command '%s'", args[0])
-		return 1
-	}
+func init() {
+	cmdMap["help"] = &helpCmd{}
 }
 
-func showHelp() {
-	fmt.Print(
-		" .----------------.  .----------------.  .----------------.  .----------------.\n" +
-			"| .--------------. || .--------------. || .--------------. || .--------------. |\n" +
-			"| | ____   ____  | || |     ____     | || |   _____      | || |  _________   | |\n" +
-			"| ||_  _| |_  _| | || |   .'    `.   | || |  |_   _|     | || | |  _   _  |  | |\n" +
-			"| |  \\ \\   / /   | || |  /  .--.  \\  | || |    | |       | || | |_/ | | \\_|  | |\n" +
-			"| |   \\ \\ / /    | || |  | |    | |  | || |    | |   _   | || |     | |      | |\n" +
-			"| |    \\ ' /     | || |  \\  `--'  /  | || |   _| |__/ |  | || |    _| |_     | |\n" +
-			"| |     \\_/      | || |   `.____.'   | || |  |________|  | || |   |_____|    | |\n" +
-			"| |              | || |              | || |              | || |              | |\n" +
-			"| '--------------' || '--------------' || '--------------' || '--------------' |\n" +
-			" '----------------'  '----------------'  '----------------'  '----------------'\n" +
-			`
+type helpCmd struct{}
+
+func (cmd *helpCmd) FlagSet() *flag.FlagSet {
+	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
+	fs.SetOutput(os.Stdout)
+	fs.Usage = func() {
+		fmt.Print(
+			" .----------------.  .----------------.  .----------------.  .----------------.\n" +
+				"| .--------------. || .--------------. || .--------------. || .--------------. |\n" +
+				"| | ____   ____  | || |     ____     | || |   _____      | || |  _________   | |\n" +
+				"| ||_  _| |_  _| | || |   .'    `.   | || |  |_   _|     | || | |  _   _  |  | |\n" +
+				"| |  \\ \\   / /   | || |  /  .--.  \\  | || |    | |       | || | |_/ | | \\_|  | |\n" +
+				"| |   \\ \\ / /    | || |  | |    | |  | || |    | |   _   | || |     | |      | |\n" +
+				"| |    \\ ' /     | || |  \\  `--'  /  | || |   _| |__/ |  | || |    _| |_     | |\n" +
+				"| |     \\_/      | || |   `.____.'   | || |  |________|  | || |   |_____|    | |\n" +
+				"| |              | || |              | || |              | || |              | |\n" +
+				"| '--------------' || '--------------' || '--------------' || '--------------' |\n" +
+				" '----------------'  '----------------'  '----------------'  '----------------'\n" +
+				`
 Usage
   volt COMMAND ARGS
 
@@ -106,4 +95,26 @@ Command
 
   version
     Show volt command version` + "\n\n")
+		//cmd.helped = true
+	}
+	return fs
+}
+
+func (cmd *helpCmd) Run(args []string) int {
+	if len(args) == 0 {
+		cmd.FlagSet().Usage()
+		return 0
+	}
+	if args[0] == "help" { // "volt help help"
+		fmt.Println("E478: Don't panic!")
+		return 0
+	}
+
+	if fs, exists := cmdMap[args[0]]; exists {
+		fs.Run([]string{"-help"})
+		return 0
+	} else {
+		logger.Errorf("Unknown command '%s'", args[0])
+		return 1
+	}
 }
diff --git a/cmd/list.go b/cmd/list.go
index 6a7fe304..5009e12a 100644
--- a/cmd/list.go
+++ b/cmd/list.go
@@ -8,13 +8,15 @@ import (
 	"github.com/vim-volt/volt/logger"
 )
 
-type listFlagsType struct {
-	helped bool
+func init() {
+	cmdMap["list"] = &listCmd{}
 }
 
-var listFlags listFlagsType
+type listCmd struct {
+	helped bool
+}
 
-func init() {
+func (cmd *listCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -31,15 +33,12 @@ Description
 		//fmt.Println("Options")
 		//fs.PrintDefaults()
 		fmt.Println()
-		listFlags.helped = true
+		cmd.helped = true
 	}
-
-	cmdFlagSet["list"] = fs
+	return fs
 }
 
-type listCmd struct{}
-
-func List(args []string) int {
+func (cmd *listCmd) Run(args []string) int {
 	profCmd := profileCmd{}
 	err := profCmd.doShow(append(
 		[]string{"-current"},
diff --git a/cmd/migrate.go b/cmd/migrate.go
index b61bb6c0..a9751c9c 100644
--- a/cmd/migrate.go
+++ b/cmd/migrate.go
@@ -11,13 +11,15 @@ import (
 	"github.com/vim-volt/volt/transaction"
 )
 
-type migrateFlagsType struct {
-	helped bool
+func init() {
+	cmdMap["migrate"] = &migrateCmd{}
 }
 
-var migrateFlags migrateFlagsType
+type migrateCmd struct {
+	helped bool
+}
 
-func init() {
+func (cmd *migrateCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -32,17 +34,12 @@ Description
 		//fmt.Println("Options")
 		//fs.PrintDefaults()
 		fmt.Println()
-		migrateFlags.helped = true
+		cmd.helped = true
 	}
-
-	cmdFlagSet["migrate"] = fs
+	return fs
 }
 
-type migrateCmd struct{}
-
-func Migrate(args []string) int {
-	cmd := migrateCmd{}
-
+func (cmd *migrateCmd) Run(args []string) int {
 	err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
 		return 0
@@ -61,10 +58,10 @@ func Migrate(args []string) int {
 	return 0
 }
 
-func (*migrateCmd) parseArgs(args []string) error {
-	fs := cmdFlagSet["migrate"]
+func (cmd *migrateCmd) parseArgs(args []string) error {
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if migrateFlags.helped {
+	if cmd.helped {
 		return ErrShowedHelp
 	}
 	return nil
diff --git a/cmd/profile.go b/cmd/profile.go
index 888021af..1e2cf04f 100644
--- a/cmd/profile.go
+++ b/cmd/profile.go
@@ -13,28 +13,17 @@ import (
 	"github.com/vim-volt/volt/transaction"
 )
 
-type profileFlagsType struct {
+type profileCmd struct {
 	helped bool
 }
 
-var profileFlags profileFlagsType
-
-type profileCmd struct{}
-
 var profileSubCmd = make(map[string]func([]string) error)
 
 func init() {
-	cmd := profileCmd{}
-	profileSubCmd["set"] = cmd.doSet
-	profileSubCmd["show"] = cmd.doShow
-	profileSubCmd["list"] = cmd.doList
-	profileSubCmd["new"] = cmd.doNew
-	profileSubCmd["destroy"] = cmd.doDestroy
-	profileSubCmd["rename"] = cmd.doRename
-	profileSubCmd["add"] = cmd.doAdd
-	profileSubCmd["rm"] = cmd.doRm
-	profileSubCmd["use"] = cmd.doUse
+	cmdMap["profile"] = &profileCmd{}
+}
 
+func (cmd *profileCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -93,15 +82,12 @@ Quick example
 
   $ volt profile use -current vimrc false   # Disable installing vimrc on current profile on "volt build"
   $ volt profile use default gvimrc true   # Enable installing gvimrc on profile default on "volt build"` + "\n\n")
-		profileFlags.helped = true
+		cmd.helped = true
 	}
-
-	cmdFlagSet["profile"] = fs
+	return fs
 }
 
-func Profile(args []string) int {
-	cmd := profileCmd{}
-
+func (cmd *profileCmd) Run(args []string) int {
 	// Parse args
 	args, err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
@@ -112,32 +98,49 @@ func Profile(args []string) int {
 		return 10
 	}
 
-	if fn, exists := profileSubCmd[args[0]]; exists {
-		err = fn(args[1:])
-		if err != nil {
-			logger.Error(err.Error())
-			return 11
-		}
+	subCmd := args[0]
+	switch subCmd {
+	case "set":
+		err = cmd.doSet(args[1:])
+	case "show":
+		err = cmd.doShow(args[1:])
+	case "list":
+		err = cmd.doList(args[1:])
+	case "new":
+		err = cmd.doNew(args[1:])
+	case "destroy":
+		err = cmd.doDestroy(args[1:])
+	case "rename":
+		err = cmd.doRename(args[1:])
+	case "add":
+		err = cmd.doAdd(args[1:])
+	case "rm":
+		err = cmd.doRm(args[1:])
+	case "use":
+		err = cmd.doUse(args[1:])
+	default:
+		logger.Error("unknown subcommand: " + subCmd)
+		return 11
+	}
+
+	if err != nil {
+		logger.Error(err.Error())
+		return 20
 	}
 
 	return 0
 }
 
 func (cmd *profileCmd) parseArgs(args []string) ([]string, error) {
-	fs := cmdFlagSet["profile"]
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if profileFlags.helped {
+	if cmd.helped {
 		return nil, ErrShowedHelp
 	}
 
 	if len(fs.Args()) == 0 {
 		return nil, errors.New("must specify subcommand: volt profile")
 	}
-
-	subCmd := fs.Args()[0]
-	if _, exists := profileSubCmd[subCmd]; !exists {
-		return nil, errors.New("unknown subcommand: " + subCmd)
-	}
 	return fs.Args(), nil
 }
 
@@ -151,7 +154,7 @@ func (*profileCmd) getCurrentProfile() (string, error) {
 
 func (cmd *profileCmd) doSet(args []string) error {
 	if len(args) == 0 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("'volt profile set' receives profile name.")
 		return nil
 	}
@@ -203,7 +206,7 @@ func (cmd *profileCmd) doSet(args []string) error {
 
 func (cmd *profileCmd) doShow(args []string) error {
 	if len(args) == 0 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("'volt profile show' receives profile name.")
 		return nil
 	}
@@ -263,7 +266,7 @@ func (cmd *profileCmd) doList(args []string) error {
 
 func (cmd *profileCmd) doNew(args []string) error {
 	if len(args) == 0 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("'volt profile new' receives profile name.")
 		return nil
 	}
@@ -309,7 +312,7 @@ func (cmd *profileCmd) doNew(args []string) error {
 
 func (cmd *profileCmd) doDestroy(args []string) error {
 	if len(args) == 0 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("'volt profile destroy' receives profile name.")
 		return nil
 	}
@@ -362,7 +365,7 @@ func (cmd *profileCmd) doDestroy(args []string) error {
 
 func (cmd *profileCmd) doRename(args []string) error {
 	if len(args) != 2 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("'volt profile rename' receives profile name.")
 		return nil
 	}
@@ -507,7 +510,7 @@ func (cmd *profileCmd) doRm(args []string) error {
 
 func (cmd *profileCmd) parseAddArgs(lockJSON *lockjson.LockJSON, subCmd string, args []string) (string, []string, error) {
 	if len(args) == 0 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Errorf("'volt profile %s' receives profile name and one or more repositories.", subCmd)
 		return "", nil, nil
 	}
@@ -561,17 +564,17 @@ func (*profileCmd) transactProfile(lockJSON *lockjson.LockJSON, profileName stri
 func (cmd *profileCmd) doUse(args []string) error {
 	// Validate arguments
 	if len(args) != 3 {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("'volt profile use' receives profile name, rc name, value.")
 		return nil
 	}
 	if args[1] != "vimrc" && args[1] != "gvimrc" {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("volt profile use: Please specify \"vimrc\" or \"gvimrc\" to the 2nd argument")
 		return nil
 	}
 	if args[2] != "true" && args[2] != "false" {
-		cmdFlagSet["profile"].Usage()
+		cmd.FlagSet().Usage()
 		logger.Error("volt profile use: Please specify \"true\" or \"false\" to the 3rd argument")
 		return nil
 	}
diff --git a/cmd/rm.go b/cmd/rm.go
index be08e4c0..874519fd 100644
--- a/cmd/rm.go
+++ b/cmd/rm.go
@@ -16,15 +16,17 @@ import (
 	"github.com/vim-volt/volt/transaction"
 )
 
-type rmFlagsType struct {
+func init() {
+	cmdMap["rm"] = &rmCmd{}
+}
+
+type rmCmd struct {
 	helped     bool
 	rmRepos    bool
 	rmPlugconf bool
 }
 
-var rmFlags rmFlagsType
-
-func init() {
+func (cmd *rmCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -49,20 +51,15 @@ Description
 		//fmt.Println("Options")
 		//fs.PrintDefaults()
 		fmt.Println()
-		rmFlags.helped = true
+		cmd.helped = true
 	}
-	fs.BoolVar(&rmFlags.rmRepos, "r", false, "remove also repository directories")
-	fs.BoolVar(&rmFlags.rmPlugconf, "p", false, "remove also plugconf files")
-
-	cmdFlagSet["rm"] = fs
+	fs.BoolVar(&cmd.rmRepos, "r", false, "remove also repository directories")
+	fs.BoolVar(&cmd.rmPlugconf, "p", false, "remove also plugconf files")
+	return fs
 }
 
-type rmCmd struct{}
-
-func Rm(args []string) int {
-	cmd := rmCmd{}
-
-	reposPathList, flags, err := cmd.parseArgs(args)
+func (cmd *rmCmd) Run(args []string) int {
+	reposPathList, err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
 		return 0
 	}
@@ -71,7 +68,7 @@ func Rm(args []string) int {
 		return 10
 	}
 
-	err = cmd.doRemove(reposPathList, flags)
+	err = cmd.doRemove(reposPathList)
 	if err != nil {
 		logger.Error("Failed to remove repository: " + err.Error())
 		return 11
@@ -87,30 +84,30 @@ func Rm(args []string) int {
 	return 0
 }
 
-func (*rmCmd) parseArgs(args []string) ([]string, *rmFlagsType, error) {
-	fs := cmdFlagSet["rm"]
+func (cmd *rmCmd) parseArgs(args []string) ([]string, error) {
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if rmFlags.helped {
-		return nil, nil, ErrShowedHelp
+	if cmd.helped {
+		return nil, ErrShowedHelp
 	}
 
 	if len(fs.Args()) == 0 {
 		fs.Usage()
-		return nil, nil, errors.New("repository was not given")
+		return nil, errors.New("repository was not given")
 	}
 
 	var reposPathList []string
 	for _, arg := range fs.Args() {
 		reposPath, err := pathutil.NormalizeRepos(arg)
 		if err != nil {
-			return nil, nil, err
+			return nil, err
 		}
 		reposPathList = append(reposPathList, reposPath)
 	}
-	return reposPathList, &rmFlags, nil
+	return reposPathList, nil
 }
 
-func (cmd *rmCmd) doRemove(reposPathList []string, flags *rmFlagsType) error {
+func (cmd *rmCmd) doRemove(reposPathList []string) error {
 	// Read lock.json
 	lockJSON, err := lockjson.Read()
 	if err != nil {
@@ -140,7 +137,7 @@ func (cmd *rmCmd) doRemove(reposPathList []string, flags *rmFlagsType) error {
 	removeCount := 0
 	for _, reposPath := range reposPathList {
 		// Remove repository directory
-		if flags.rmRepos {
+		if cmd.rmRepos {
 			fullReposPath := pathutil.FullReposPathOf(reposPath)
 			if pathutil.Exists(fullReposPath) {
 				if err = cmd.removeRepos(fullReposPath); err != nil {
@@ -153,7 +150,7 @@ func (cmd *rmCmd) doRemove(reposPathList []string, flags *rmFlagsType) error {
 		}
 
 		// Remove plugconf file
-		if flags.rmPlugconf {
+		if cmd.rmPlugconf {
 			plugconfPath := pathutil.PlugconfOf(reposPath)
 			if pathutil.Exists(plugconfPath) {
 				if err = cmd.removePlugconf(plugconfPath); err != nil {
diff --git a/cmd/self_upgrade.go b/cmd/self_upgrade.go
index 353aedc8..7f0c2314 100644
--- a/cmd/self_upgrade.go
+++ b/cmd/self_upgrade.go
@@ -19,14 +19,16 @@ import (
 	"github.com/vim-volt/volt/logger"
 )
 
-type selfUpgradeFlagsType struct {
+func init() {
+	cmdMap["self-upgrade"] = &selfUpgradeCmd{}
+}
+
+type selfUpgradeCmd struct {
 	helped bool
 	check  bool
 }
 
-var selfUpgradeFlags selfUpgradeFlagsType
-
-func init() {
+func (cmd *selfUpgradeCmd) FlagSet() *flag.FlagSet {
 	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	fs.SetOutput(os.Stdout)
 	fs.Usage = func() {
@@ -39,19 +41,14 @@ Description
 		//fmt.Println("Options")
 		//fs.PrintDefaults()
 		fmt.Println()
-		selfUpgradeFlags.helped = true
+		cmd.helped = true
 	}
-	fs.BoolVar(&selfUpgradeFlags.check, "check", false, "only checks the newer version is available")
-
-	cmdFlagSet["self-upgrade"] = fs
+	fs.BoolVar(&cmd.check, "check", false, "only checks the newer version is available")
+	return fs
 }
 
-type selfUpgradeCmd struct{}
-
-func SelfUpgrade(args []string) int {
-	cmd := selfUpgradeCmd{}
-
-	flags, err := cmd.parseArgs(args)
+func (cmd *selfUpgradeCmd) Run(args []string) int {
+	err := cmd.parseArgs(args)
 	if err == ErrShowedHelp {
 		return 0
 	}
@@ -67,7 +64,7 @@ func SelfUpgrade(args []string) int {
 		}
 	} else {
 		latestURL := "https://api.github.com/repos/vim-volt/volt/releases/latest"
-		if err = cmd.doSelfUpgrade(flags, latestURL); err != nil {
+		if err = cmd.doSelfUpgrade(latestURL); err != nil {
 			logger.Error("Failed to self-upgrade: " + err.Error())
 			return 12
 		}
@@ -76,13 +73,13 @@ func SelfUpgrade(args []string) int {
 	return 0
 }
 
-func (*selfUpgradeCmd) parseArgs(args []string) (*selfUpgradeFlagsType, error) {
-	fs := cmdFlagSet["self-upgrade"]
+func (cmd *selfUpgradeCmd) parseArgs(args []string) error {
+	fs := cmd.FlagSet()
 	fs.Parse(args)
-	if selfUpgradeFlags.helped {
-		return nil, ErrShowedHelp
+	if cmd.helped {
+		return ErrShowedHelp
 	}
-	return &selfUpgradeFlags, nil
+	return nil
 }
 
 func (cmd *selfUpgradeCmd) doCleanUp(ppidStr string) error {
@@ -135,9 +132,9 @@ type releaseAsset struct {
 	Name               string `json:"name"`
 }
 
-func (cmd *selfUpgradeCmd) doSelfUpgrade(flags *selfUpgradeFlagsType, latestURL string) error {
-	// Check the latest binary
-	release, err := cmd.check(latestURL)
+func (cmd *selfUpgradeCmd) doSelfUpgrade(latestURL string) error {
+	// Check the latest binary info
+	release, err := cmd.checkLatest(latestURL)
 	if err != nil {
 		return err
 	}
@@ -157,7 +154,7 @@ func (cmd *selfUpgradeCmd) doSelfUpgrade(flags *selfUpgradeFlagsType, latestURL
 	fmt.Println(release.Body)
 	fmt.Println("---")
 
-	if flags.check {
+	if cmd.check {
 		return nil
 	}
 
@@ -166,15 +163,14 @@ func (cmd *selfUpgradeCmd) doSelfUpgrade(flags *selfUpgradeFlagsType, latestURL
 	if err != nil {
 		return err
 	}
-	{
-		latestFile, err := os.OpenFile(voltExe+".latest", os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0777)
-		if err != nil {
-			return err
-		}
-		defer latestFile.Close()
-		if err = cmd.download(latestFile, release); err != nil {
-			return err
-		}
+	latestFile, err := os.OpenFile(voltExe+".latest", os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0777)
+	if err != nil {
+		return err
+	}
+	err = cmd.download(latestFile, release)
+	latestFile.Close()
+	if err != nil {
+		return err
 	}
 
 	// Rename dir/volt[.exe] to dir/volt[.exe].old
@@ -204,7 +200,7 @@ func (*selfUpgradeCmd) getExecutablePath() (string, error) {
 	return filepath.EvalSymlinks(exe)
 }
 
-func (*selfUpgradeCmd) check(url string) (*latestRelease, error) {
+func (*selfUpgradeCmd) checkLatest(url string) (*latestRelease, error) {
 	content, err := httputil.GetContent(url)
 	if err != nil {
 		return nil, err
diff --git a/cmd/version.go b/cmd/version.go
index 51c8d0ee..38d4d751 100644
--- a/cmd/version.go
+++ b/cmd/version.go
@@ -2,16 +2,49 @@ package cmd
 
 import (
 	"errors"
+	"flag"
 	"fmt"
+	"os"
 	"regexp"
 	"strconv"
 )
 
-var voltVersion string = "v0.2.1"
+var voltVersion string = "v0.2.2"
 
-func Version(args []string) int {
-	fmt.Printf("volt version: %s\n", voltVersion)
+func init() {
+	cmdMap["version"] = &versionCmd{}
+}
+
+type versionCmd struct {
+	helped bool
+}
+
+func (cmd *versionCmd) FlagSet() *flag.FlagSet {
+	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
+	fs.SetOutput(os.Stdout)
+	fs.Usage = func() {
+		fmt.Print(`
+Usage
+  volt version [-help]
 
+Description
+  Show current version of volt.` + "\n\n")
+		//fmt.Println("Options")
+		//fs.PrintDefaults()
+		fmt.Println()
+		cmd.helped = true
+	}
+	return fs
+}
+
+func (cmd *versionCmd) Run(args []string) int {
+	fs := cmd.FlagSet()
+	fs.Parse(args)
+	if cmd.helped {
+		return 0
+	}
+
+	fmt.Printf("volt version: %s\n", voltVersion)
 	return 0
 }
 
diff --git a/fileutil/copydir.go b/fileutil/copydir.go
index 43485fd6..f0047b43 100644
--- a/fileutil/copydir.go
+++ b/fileutil/copydir.go
@@ -10,7 +10,7 @@ import (
 
 // CopyDir recursively copies a directory tree, attempting to preserve permissions.
 // Source directory must exist, destination directory must *not* exist.
-func CopyDir(src, dst string, buf []byte, perm os.FileMode, invalidType os.FileMode) error {
+func CopyDir(src, dst string, buf []byte, perm os.FileMode, ignoreType os.FileMode) error {
 	if err := os.MkdirAll(dst, perm); err != nil {
 		return err
 	}
@@ -26,15 +26,15 @@ func CopyDir(src, dst string, buf []byte, perm os.FileMode, invalidType os.FileM
 	}
 
 	for i := range entries {
-		if entries[i].Mode()&invalidType != 0 {
-			return newInvalidType(entries[i].Name())
+		if entries[i].Mode()&ignoreType != 0 {
+			continue
 		}
 
 		srcPath := filepath.Join(src, entries[i].Name())
 		dstPath := filepath.Join(dst, entries[i].Name())
 
 		if entries[i].IsDir() {
-			if err = CopyDir(srcPath, dstPath, buf, entries[i].Mode(), invalidType); err != nil {
+			if err = CopyDir(srcPath, dstPath, buf, entries[i].Mode(), ignoreType); err != nil {
 				return err
 			}
 		} else {
diff --git a/fileutil/link.go b/fileutil/link.go
index 376d1499..5154e878 100644
--- a/fileutil/link.go
+++ b/fileutil/link.go
@@ -8,7 +8,7 @@ import (
 
 // TryLinkDir recursively copies a directory tree, attempting to preserve permissions.
 // Source directory must exist, destination directory must *not* exist.
-func TryLinkDir(src, dst string, buf []byte, perm os.FileMode, invalidType os.FileMode) error {
+func TryLinkDir(src, dst string, buf []byte, perm os.FileMode, ignoreType os.FileMode) error {
 	if err := os.MkdirAll(dst, perm); err != nil {
 		return err
 	}
@@ -23,15 +23,15 @@ func TryLinkDir(src, dst string, buf []byte, perm os.FileMode, invalidType os.Fi
 	}
 
 	for i := range entries {
-		if entries[i].Mode()&invalidType != 0 {
-			return newInvalidType(entries[i].Name())
+		if entries[i].Mode()&ignoreType != 0 {
+			continue
 		}
 
 		srcPath := filepath.Join(src, entries[i].Name())
 		dstPath := filepath.Join(dst, entries[i].Name())
 
 		if entries[i].IsDir() {
-			if err = TryLinkDir(srcPath, dstPath, buf, entries[i].Mode(), invalidType); err != nil {
+			if err = TryLinkDir(srcPath, dstPath, buf, entries[i].Mode(), ignoreType); err != nil {
 				return err
 			}
 		} else {
diff --git a/main.go b/main.go
index 5c5b083f..9ef79bb3 100644
--- a/main.go
+++ b/main.go
@@ -1,3 +1,5 @@
+// +build go1.9
+
 package main
 
 import (
@@ -18,31 +20,5 @@ func Main() int {
 	if len(os.Args) <= 1 {
 		os.Args = append(os.Args, "help")
 	}
-	switch os.Args[1] {
-	case "get":
-		return cmd.Get(os.Args[2:])
-	case "rm":
-		return cmd.Rm(os.Args[2:])
-	case "enable":
-		return cmd.Enable(os.Args[2:])
-	case "disable":
-		return cmd.Disable(os.Args[2:])
-	case "list":
-		return cmd.List(os.Args[2:])
-	case "profile":
-		return cmd.Profile(os.Args[2:])
-	case "build":
-		return cmd.Build(os.Args[2:])
-	case "migrate":
-		return cmd.Migrate(os.Args[2:])
-	case "self-upgrade":
-		return cmd.SelfUpgrade(os.Args[2:])
-	case "version":
-		return cmd.Version(os.Args[2:])
-	case "help":
-		return cmd.Help(os.Args[2:])
-	default:
-		logger.Error("Unknown command '" + os.Args[1] + "'")
-		return 3
-	}
+	return cmd.Run(os.Args[1], os.Args[2:])
 }