// EnsureGoVendor ensures that the Go version is correct.
func EnsureGoVendor() {
	// 6l was removed in 1.5, when vendoring was introduced.
	cmd := exec.Command("go", "tool", "6l")
	if _, err := cmd.CombinedOutput(); err == nil {
		msg.Warn("You must install the Go 1.5 or greater toolchain to work with Glide.\n")
		os.Exit(1)
	}
	if os.Getenv("GO15VENDOREXPERIMENT") != "1" {
		msg.Warn("To use Glide, you must set GO15VENDOREXPERIMENT=1\n")
		os.Exit(1)
	}

	// Verify the setup isn't for the old version of glide. That is, this is
	// no longer assuming the _vendor directory as the GOPATH. Inform of
	// the change.
	if _, err := os.Stat("_vendor/"); err == nil {
		msg.Warn(`Your setup appears to be for the previous version of Glide.
Previously, vendor packages were stored in _vendor/src/ and
_vendor was set as your GOPATH. As of Go 1.5 the go tools
recognize the vendor directory as a location for these
files. Glide has embraced this. Please remove the _vendor
directory or move the _vendor/src/ directory to vendor/.` + "\n")
		os.Exit(1)
	}
}

// Get fetches one or more dependencies and installs.
//
// This includes resolving dependency resolution and re-generating the lock file.
func Get(names []string, installer *repo.Installer, insecure, skipRecursive bool) {
	base := gpath.Basepath()
	EnsureGopath()
	EnsureVendorDir()
	conf := EnsureConfig()
	glidefile, err := gpath.Glide()
	if err != nil {
		msg.Die("Could not find Glide file: %s", err)
	}

	// Add the packages to the config.
	if err := addPkgsToConfig(conf, names, insecure); err != nil {
		msg.Die("Failed to get new packages: %s", err)
	}

	// Fetch the new packages. Can't resolve versions via installer.Update if
	// get is called while the vendor/ directory is empty so we checkout
	// everything.
	installer.Checkout(conf, false)

	// Prior to resolving dependencies we need to start working with a clone
	// of the conf because we'll be making real changes to it.
	confcopy := conf.Clone()

	if !skipRecursive {
		// Get all repos and update them.
		// TODO: Can we streamline this in any way? The reason that we update all
		// of the dependencies is that we need to re-negotiate versions. For example,
		// if an existing dependency has the constraint >1.0 and this new package
		// adds the constraint <2.0, then this may re-resolve the existing dependency
		// to be between 1.0 and 2.0. But changing that dependency may then result
		// in that dependency's dependencies changing... so we sorta do the whole
		// thing to be safe.
		err = installer.Update(confcopy)
		if err != nil {
			msg.Die("Could not update packages: %s", err)
		}
	}

	// Set Reference
	if err := repo.SetReference(confcopy); err != nil {
		msg.Error("Failed to set references: %s", err)
	}

	// VendoredCleanup
	if installer.UpdateVendored {
		repo.VendoredCleanup(confcopy)
	}

	// Write YAML
	if err := conf.WriteFile(glidefile); err != nil {
		msg.Die("Failed to write glide YAML file: %s", err)
	}
	if !skipRecursive {
		// Write lock
		writeLock(conf, confcopy, base)
	} else {
		msg.Warn("Skipping lockfile generation because full dependency tree is not being calculated")
	}
}

// Parse parses a GPM-flavored Godeps file.
func Parse(dir string) ([]*cfg.Dependency, error) {
	path := filepath.Join(dir, "Godeps")
	if i, err := os.Stat(path); err != nil {
		return []*cfg.Dependency{}, nil
	} else if i.IsDir() {
		msg.Info("Godeps is a directory. This is probably a Godep project.\n")
		return []*cfg.Dependency{}, nil
	}
	msg.Info("Found Godeps file.\n")

	buf := []*cfg.Dependency{}

	file, err := os.Open(path)
	if err != nil {
		return buf, err
	}
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		parts, ok := parseGodepsLine(scanner.Text())
		if ok {
			dep := &cfg.Dependency{Name: parts[0]}
			if len(parts) > 1 {
				dep.Reference = parts[1]
			}
			buf = append(buf, dep)
		}
	}
	if err := scanner.Err(); err != nil {
		msg.Warn("Scan failed: %s\n", err)
		return buf, err
	}

	return buf, nil
}

func (i *Installer) List(conf *cfg.Config) []*cfg.Dependency {
	base := "."
	vpath := i.VendorPath()

	ic := newImportCache()

	v := &VersionHandler{
		Destination: vpath,
		Use:         ic,
		Imported:    make(map[string]bool),
		Conflicts:   make(map[string]bool),
		Config:      conf,
	}

	// Update imports
	res, err := dependency.NewResolver(base)
	if err != nil {
		msg.Die("Failed to create a resolver: %s", err)
	}
	res.Config = conf
	res.VersionHandler = v

	msg.Info("Resolving imports")
	_, err = allPackages(conf.Imports, res)
	if err != nil {
		msg.Die("Failed to retrieve a list of dependencies: %s", err)
	}

	msg.Warn("devImports not resolved.")

	return conf.Imports
}

func guessImportDeps(base string, config *cfg.Config) {
	msg.Info("Attempting to import from other package managers (use --skip-import to skip)")
	deps := []*cfg.Dependency{}
	absBase, err := filepath.Abs(base)
	if err != nil {
		msg.Die("Failed to resolve location of %s: %s", base, err)
	}

	if d, ok := guessImportGodep(absBase); ok {
		msg.Info("Importing Godep configuration")
		msg.Warn("Godep uses commit id versions. Consider using Semantic Versions with Glide")
		deps = d
	} else if d, ok := guessImportGPM(absBase); ok {
		msg.Info("Importing GPM configuration")
		deps = d
	} else if d, ok := guessImportGB(absBase); ok {
		msg.Info("Importing GB configuration")
		deps = d
	}

	for _, i := range deps {
		if i.Reference == "" {
			msg.Info("--> Found imported reference to %s", i.Name)
		} else {
			msg.Info("--> Found imported reference to %s at revision %s", i.Name, i.Reference)
		}

		config.Imports = append(config.Imports, i)
	}
}

func singleWarn(ft string, v ...interface{}) {
	m := fmt.Sprintf(ft, v...)
	_, f := warningMessage[m]
	if !f {
		msg.Warn(m)
		warningMessage[m] = true
	}
}

// EnsureConfig loads and returns a config file.
//
// Any error will cause an immediate exit, with an error printed to Stderr.
func EnsureConfig() *cfg.Config {
	yamlpath, err := gpath.Glide()
	if err != nil {
		msg.ExitCode(2)
		msg.Die("Failed to find %s file in directory tree: %s", gpath.GlideFile, err)
	}

	yml, err := ioutil.ReadFile(yamlpath)
	if err != nil {
		msg.ExitCode(2)
		msg.Die("Failed to load %s: %s", yamlpath, err)
	}
	conf, err := cfg.ConfigFromYaml(yml)
	if err != nil {
		msg.ExitCode(3)
		msg.Die("Failed to parse %s: %s", yamlpath, err)
	}

	b := filepath.Dir(yamlpath)
	buildContext, err := util.GetBuildContext()
	if err != nil {
		msg.Die("Failed to build an import context while ensuring config: %s", err)
	}
	cwd, err := os.Getwd()
	if err != nil {
		msg.Err("Unable to get the current working directory")
	} else {
		// Determining a package name requires a relative path
		b, err = filepath.Rel(b, cwd)
		if err == nil {
			name := buildContext.PackageName(b)
			if name != conf.Name {
				msg.Warn("The name listed in the config file (%s) does not match the current location (%s)", conf.Name, name)
			}
		} else {
			msg.Warn("Problem finding the config file path (%s) relative to the current directory (%s): %s", b, cwd, err)
		}
	}

	err = mirrors.Load()
	if err != nil {
		msg.Err("Unable to load mirrors: %s", err)
	}

	return conf
}

// EnsureGoVendor ensures that the Go version is correct.
func EnsureGoVendor() {
	// 6l was removed in 1.5, when vendoring was introduced.
	cmd := exec.Command(goExecutable(), "tool", "6l")
	if _, err := cmd.CombinedOutput(); err == nil {
		msg.Warn("You must install the Go 1.5 or greater toolchain to work with Glide.\n")
		os.Exit(1)
	}

	// Check if this is go15, which requires GO15VENDOREXPERIMENT
	// Any release after go15 does not require that env var.
	cmd = exec.Command(goExecutable(), "version")
	if out, err := cmd.CombinedOutput(); err != nil {
		msg.Err("Error getting version: %s.\n", err)
		os.Exit(1)
	} else if strings.HasPrefix(string(out), "go version 1.5") {
		// This works with 1.5 and 1.6.
		cmd = exec.Command(goExecutable(), "env", "GO15VENDOREXPERIMENT")
		if out, err := cmd.CombinedOutput(); err != nil {
			msg.Err("Error looking for $GOVENDOREXPERIMENT: %s.\n", err)
			os.Exit(1)
		} else if strings.TrimSpace(string(out)) != "1" {
			msg.Err("To use Glide, you must set GO15VENDOREXPERIMENT=1")
			os.Exit(1)
		}
	}

	// In the case where vendoring is explicitly disabled, balk.
	if os.Getenv("GO15VENDOREXPERIMENT") == "0" {
		msg.Err("To use Glide, you must set GO15VENDOREXPERIMENT=1")
		os.Exit(1)
	}

	// Verify the setup isn't for the old version of glide. That is, this is
	// no longer assuming the _vendor directory as the GOPATH. Inform of
	// the change.
	if _, err := os.Stat("_vendor/"); err == nil {
		msg.Warn(`Your setup appears to be for the previous version of Glide.
Previously, vendor packages were stored in _vendor/src/ and
_vendor was set as your GOPATH. As of Go 1.5 the go tools
recognize the vendor directory as a location for these
files. Glide has embraced this. Please remove the _vendor
directory or move the _vendor/src/ directory to vendor/.` + "\n")
		os.Exit(1)
	}
}

// Install installs a vendor directory based on an existing Glide configuration.
func Install(installer *repo.Installer, stripVendor bool) {
	cache.SystemLock()

	base := "."
	// Ensure GOPATH
	EnsureGopath()
	EnsureVendorDir()
	conf := EnsureConfig()

	// Lockfile exists
	if !gpath.HasLock(base) {
		msg.Info("Lock file (glide.lock) does not exist. Performing update.")
		Update(installer, false, stripVendor)
		return
	}
	// Load lockfile
	lock, err := cfg.ReadLockFile(filepath.Join(base, gpath.LockFile))
	if err != nil {
		msg.Die("Could not load lockfile.")
	}
	// Verify lockfile hasn't changed
	hash, err := conf.Hash()
	if err != nil {
		msg.Die("Could not load lockfile.")
	} else if hash != lock.Hash {
		fmt.Println(hash, lock.Hash)
		foo, _ := conf.Marshal()
		fmt.Println(string(foo))
		msg.Warn("Lock file may be out of date. Hash check of YAML failed. You may need to run 'update'")
	}

	// Install
	newConf, err := installer.Install(lock, conf)
	if err != nil {
		msg.Die("Failed to install: %s", err)
	}

	msg.Info("Setting references.")

	// Set reference
	if err := repo.SetReference(newConf, installer.ResolveTest); err != nil {
		msg.Die("Failed to set references: %s (Skip to cleanup)", err)
	}

	err = installer.Export(newConf)
	if err != nil {
		msg.Die("Unable to export dependencies to vendor directory: %s", err)
	}

	if stripVendor {
		msg.Info("Removing nested vendor and Godeps/_workspace directories...")
		err := gpath.StripVendor()
		if err != nil {
			msg.Err("Unable to strip vendor directories: %s", err)
		}
	}
}

// NotFound attempts to retrieve a package when not found in the local vendor/
// folder. It will attempt to get it from the remote location info.
func (m *MissingPackageHandler) NotFound(pkg string, addTest bool) (bool, error) {
	root := util.GetRootFromPackage(pkg)
	// Skip any references to the root package.
	if root == m.Config.Name {
		return false, nil
	}

	dest := filepath.Join(m.destination, root)

	// This package may have been placed on the list to look for when it wasn't
	// downloaded but it has since been downloaded before coming to this entry.
	if _, err := os.Stat(dest); err == nil {
		// Make sure the location contains files. It may be an empty directory.
		empty, err := gpath.IsDirectoryEmpty(dest)
		if err != nil {
			return false, err
		}
		if empty {
			msg.Warn("%s is an existing location with no files. Fetching a new copy of the dependency.", dest)
			msg.Debug("Removing empty directory %s", dest)
			err := os.RemoveAll(dest)
			if err != nil {
				msg.Debug("Installer error removing directory %s: %s", dest, err)
				return false, err
			}
		} else {
			msg.Debug("Found %s", dest)
			return true, nil
		}
	}

	msg.Info("Fetching %s into %s", pkg, m.destination)

	d := m.Config.Imports.Get(root)
	if d == nil && addTest {
		d = m.Config.DevImports.Get(root)
	}

	// If the dependency is nil it means the Config doesn't yet know about it.
	if d == nil {
		d, _ = m.Use.Get(root)
		// We don't know about this dependency so we create a basic instance.
		if d == nil {
			d = &cfg.Dependency{Name: root}
		}
		if addTest {
			m.Config.DevImports = append(m.Config.DevImports, d)
		} else {
			m.Config.Imports = append(m.Config.Imports, d)
		}
	}
	if err := VcsGet(d, dest, m.home, m.cache, m.cacheGopath, m.useGopath); err != nil {
		return false, err
	}
	return true, nil
}

func buildPath(path string) error {
	msg.Info("Running go build %s\n", path)
	// . in a filepath.Join is removed so it needs to be prepended separately.
	p := "." + string(filepath.Separator) + filepath.Join("vendor", path)
	out, err := exec.Command("go", "install", p).CombinedOutput()
	if err != nil {
		msg.Warn("Failed to run 'go install' for %s: %s", path, string(out))
	}
	return err
}

func walkDeps(b *util.BuildCtxt, base, myName string) []string {
	externalDeps := []string{}
	filepath.Walk(base, func(path string, fi os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if !dependency.IsSrcDir(fi) {
			if fi.IsDir() {
				return filepath.SkipDir
			}
			return nil
		}

		var imps []string
		pkg, err := b.ImportDir(path, 0)
		if err != nil && strings.HasPrefix(err.Error(), "found packages ") {
			// If we got here it's because a package and multiple packages
			// declared. This is often because of an example with a package
			// or main but +build ignore as a build tag. In that case we
			// try to brute force the packages with a slower scan.
			imps, _, err = dependency.IterativeScan(path)
			if err != nil {
				msg.Err("Error walking dependencies for %s: %s", path, err)
				return err
			}
		} else if err != nil {
			if !strings.HasPrefix(err.Error(), "no buildable Go source") {
				msg.Warn("Error: %s (%s)", err, path)
				// Not sure if we should return here.
				//return err
			}
		} else {
			imps = pkg.Imports
		}

		if pkg.Goroot {
			return nil
		}

		for _, imp := range imps {
			//if strings.HasPrefix(imp, myName) {
			////Info("Skipping %s because it is a subpackage of %s", imp, myName)
			//continue
			//}
			if imp == myName {
				continue
			}
			externalDeps = append(externalDeps, imp)
		}

		return nil
	})
	return externalDeps
}

// Rebuild rebuilds '.a' files for a project.
//
// Prior to Go 1.4, this could substantially reduce time on incremental compiles.
// It remains to be seen whether this is tremendously beneficial to modern Go
// programs.
func Rebuild() {
	msg.Warn("The rebuild command is deprecated and will be removed in a future version")
	msg.Warn("Use the go install command instead")
	conf := EnsureConfig()
	vpath, err := gpath.Vendor()
	if err != nil {
		msg.Die("Could not get vendor path: %s", err)
	}

	msg.Info("Building dependencies.\n")

	if len(conf.Imports) == 0 {
		msg.Info("No dependencies found. Nothing built.\n")
		return
	}

	for _, dep := range conf.Imports {
		if err := buildDep(dep, vpath); err != nil {
			msg.Warn("Failed to build %s: %s\n", dep.Name, err)
		}
	}
}

// NoVendor generates a list of source code directories, excepting `vendor/`.
//
// If "onlyGo" is true, only folders that have Go code in them will be returned.
//
// If suffix is true, this will append `/...` to every directory.
func NoVendor(path string, onlyGo, suffix bool) {
	// This is responsible for printing the results of noVend.
	paths, err := noVend(path, onlyGo, suffix)
	if err != nil {
		msg.Error("Failed to walk file tree: %s", err)
		msg.Warn("FIXME: NoVendor should exit with non-zero exit code.")
		return
	}

	for _, p := range paths {
		msg.Puts(p)
	}
}

// Update updates all dependencies.
//
// It begins with the dependencies in the config file, but also resolves
// transitive dependencies. The returned lockfile has all of the dependencies
// listed, but the version reconciliation has not been done.
//
// In other words, all versions in the Lockfile will be empty.
func (i *Installer) Update(conf *cfg.Config) error {
	base := "."
	vpath := i.VendorPath()

	ic := newImportCache()

	m := &MissingPackageHandler{
		destination: vpath,

		cache:          i.UseCache,
		cacheGopath:    i.UseCacheGopath,
		useGopath:      i.UseGopath,
		home:           i.Home,
		force:          i.Force,
		updateVendored: i.UpdateVendored,
		Config:         conf,
		Use:            ic,
		updated:        i.Updated,
	}

	v := &VersionHandler{
		Destination: vpath,
		Use:         ic,
		Imported:    make(map[string]bool),
		Conflicts:   make(map[string]bool),
		Config:      conf,
	}

	// Update imports
	res, err := dependency.NewResolver(base)
	if err != nil {
		msg.Die("Failed to create a resolver: %s", err)
	}
	res.Config = conf
	res.Handler = m
	res.VersionHandler = v
	res.ResolveAllFiles = i.ResolveAllFiles
	msg.Info("Resolving imports")
	_, err = allPackages(conf.Imports, res)
	if err != nil {
		msg.Die("Failed to retrieve a list of dependencies: %s", err)
	}

	if len(conf.DevImports) > 0 {
		msg.Warn("dev imports not resolved.")
	}

	err = ConcurrentUpdate(conf.Imports, vpath, i, conf)

	return err
}

// SetVersion sets the version for a package. If that package version is already
// set it handles the case by:
// - keeping the already set version
// - proviting messaging about the version conflict
// TODO(mattfarina): The way version setting happens can be improved. Currently not optimal.
func (d *VersionHandler) SetVersion(pkg string) (e error) {
	root := util.GetRootFromPackage(pkg)

	// Skip any references to the root package.
	if root == d.Config.Name {
		return nil
	}

	v := d.Config.Imports.Get(root)

	dep, req := d.Use.Get(root)
	if dep != nil && v != nil {
		if v.Reference == "" && dep.Reference != "" {
			v.Reference = dep.Reference
			// Clear the pin, if set, so the new version can be used.
			v.Pin = ""
			dep = v
		} else if v.Reference != "" && dep.Reference != "" && v.Reference != dep.Reference {
			dest := filepath.Join(d.Destination, filepath.FromSlash(v.Name))
			dep = determineDependency(v, dep, dest, req)
		} else {
			dep = v
		}

	} else if v != nil {
		dep = v
	} else if dep != nil {
		// We've got an imported dependency to use and don't already have a
		// record of it. Append it to the Imports.
		d.Config.Imports = append(d.Config.Imports, dep)
	} else {
		// If we've gotten here we don't have any depenency objects.
		r, sp := util.NormalizeName(pkg)
		dep = &cfg.Dependency{
			Name: r,
		}
		if sp != "" {
			dep.Subpackages = []string{sp}
		}
		d.Config.Imports = append(d.Config.Imports, dep)
	}

	err := VcsVersion(dep, d.Destination)
	if err != nil {
		msg.Warn("Unable to set version on %s to %s. Err: %s", root, dep.Reference, err)
		e = err
	}

	return
}

// ConcurrentUpdate takes a list of dependencies and updates in parallel.
func ConcurrentUpdate(deps []*cfg.Dependency, cwd string, i *Installer) error {
	done := make(chan struct{}, concurrentWorkers)
	in := make(chan *cfg.Dependency, concurrentWorkers)
	var wg sync.WaitGroup
	var lock sync.Mutex
	var returnErr error

	msg.Info("Downloading dependencies. Please wait...")

	for ii := 0; ii < concurrentWorkers; ii++ {
		go func(ch <-chan *cfg.Dependency) {
			for {
				select {
				case dep := <-ch:
					dest := filepath.Join(i.VendorPath(), dep.Name)
					if err := VcsUpdate(dep, dest, i.Home, i.UseCache, i.UseCacheGopath, i.UseGopath, i.Force, i.UpdateVendored); err != nil {
						msg.Warn("Update failed for %s: %s\n", dep.Name, err)
						// Capture the error while making sure the concurrent
						// operations don't step on each other.
						lock.Lock()
						if returnErr == nil {
							returnErr = err
						} else {
							returnErr = cli.NewMultiError(returnErr, err)
						}
						lock.Unlock()
					}
					wg.Done()
				case <-done:
					return
				}
			}
		}(in)
	}

	for _, dep := range deps {
		wg.Add(1)
		in <- dep
	}

	wg.Wait()

	// Close goroutines setting the version
	for ii := 0; ii < concurrentWorkers; ii++ {
		done <- struct{}{}
	}

	return returnErr
}

// ListDeps lists all of the dependencies of the current project.
//
// Params:
//  - dir (string): basedir
//  - deep (bool): whether to do a deep scan or a shallow scan
//
// Returns:
//
func ListDeps(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	basedir := p.Get("dir", ".").(string)
	deep := p.Get("deep", true).(bool)

	basedir, err := filepath.Abs(basedir)
	if err != nil {
		return nil, err
	}

	r, err := dependency.NewResolver(basedir)
	if err != nil {
		return nil, err
	}
	h := &dependency.DefaultMissingPackageHandler{Missing: []string{}, Gopath: []string{}}
	r.Handler = h

	sortable, err := r.ResolveLocal(deep)
	if err != nil {
		return nil, err
	}

	sort.Strings(sortable)

	fmt.Println("INSTALLED packages:")
	for _, k := range sortable {
		v, err := filepath.Rel(basedir, k)
		if err != nil {
			msg.Warn("Failed to Rel path: %s", err)
			v = k
		}
		fmt.Printf("\t%s\n", v)
	}

	if len(h.Missing) > 0 {
		fmt.Println("\nMISSING packages:")
		for _, pkg := range h.Missing {
			fmt.Printf("\t%s\n", pkg)
		}
	}
	if len(h.Gopath) > 0 {
		fmt.Println("\nGOPATH packages:")
		for _, pkg := range h.Gopath {
			fmt.Printf("\t%s\n", pkg)
		}
	}

	return nil, nil
}

// MirrorsRemove removes a mirrors setting
func MirrorsRemove(k string) error {
	if k == "" {
		msg.Err("The mirror to remove is required")
		return nil
	}

	home := gpath.Home()

	op := filepath.Join(home, "mirrors.yaml")

	if _, err := os.Stat(op); os.IsNotExist(err) {
		msg.Err("mirrors.yaml file not found")
		return nil
	}

	ov, err := mirrors.ReadMirrorsFile(op)
	if err != nil {
		msg.Die("Unable to read mirrors.yaml file: %s", err)
	}

	var nre mirrors.MirrorRepos
	var found bool
	for _, re := range ov.Repos {
		if re.Original != k {
			nre = append(nre, re)
		} else {
			found = true
		}
	}

	if !found {
		msg.Warn("%s was not found in mirrors", k)
	} else {
		msg.Info("%s was removed from mirrors", k)
		ov.Repos = nre

		err = ov.WriteFile(op)
		if err != nil {
			msg.Err("Error writing mirrors.yaml file: %s", err)
		} else {
			msg.Info("mirrors.yaml written with changes")
		}
	}

	return nil
}

// ConcurrentUpdate takes a list of dependencies and updates in parallel.
func ConcurrentUpdate(deps []*cfg.Dependency, cwd string, i *Installer) error {
	done := make(chan struct{}, concurrentWorkers)
	in := make(chan *cfg.Dependency, concurrentWorkers)
	var wg sync.WaitGroup
	var lock sync.Mutex
	var returnErr error

	for ii := 0; ii < concurrentWorkers; ii++ {
		go func(ch <-chan *cfg.Dependency) {
			for {
				select {
				case dep := <-ch:
					if err := VcsUpdate(dep, cwd, i); err != nil {
						msg.Warn("Update failed for %s: %s\n", dep.Name, err)
						// Capture the error while making sure the concurrent
						// operations don't step on each other.
						lock.Lock()
						if returnErr == nil {
							returnErr = err
						} else {
							returnErr = cli.NewMultiError(returnErr, err)
						}
						lock.Unlock()
					}
					wg.Done()
				case <-done:
					return
				}
			}
		}(in)
	}

	for _, dep := range deps {
		wg.Add(1)
		in <- dep
	}

	wg.Wait()

	// Close goroutines setting the version
	for ii := 0; ii < concurrentWorkers; ii++ {
		done <- struct{}{}
	}

	return returnErr
}