[errors] de-specialize Transient in favor of Tags.

cipd/client/cli/main.go

 // Copyright 2014 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package cli
 
 import (
         "crypto/sha1"
         "encoding/hex"
         "encoding/json"
         "flag"
         "fmt"
         "io"
         "io/ioutil"
         "net/http"
         "os"
         "path/filepath"
         "strings"
         "sync"
         "time"
 
         "github.com/kardianos/osext"
         "github.com/maruel/subcommands"
         "golang.org/x/net/context"
 
         "github.com/luci/luci-go/common/auth"
         "github.com/luci/luci-go/common/cli"
-        "github.com/luci/luci-go/common/errors"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/common/logging/gologger"
+        "github.com/luci/luci-go/common/retry"
 
         "github.com/luci/luci-go/client/authcli"
 
         "github.com/luci/luci-go/cipd/client/cipd"
         "github.com/luci/luci-go/cipd/client/cipd/common"
         "github.com/luci/luci-go/cipd/client/cipd/ensure"
         "github.com/luci/luci-go/cipd/client/cipd/local"
         "github.com/luci/luci-go/cipd/version"
 )
 
@@ skipping 795 matching lines @@
 }
 
 func (c *checkUpdatesRun) Run(a subcommands.Application, args []string, env subcommands.Env) int {
         if !c.checkArgs(args, 0, 0) {
                 return 1
         }
         ctx := cli.GetContext(a, c, env)
         _, actions, err := ensurePackages(ctx, c.rootDir, c.ensureFile, true, c.clientOptions)
         if err != nil {
                 ret := c.done(actions, err)
-                if errors.IsTransient(err) {
+                if retry.Tag.In(err) {
                         return ret // fail as usual
                 }
                 return 0 // on fatal errors ask puppet to run 'ensure' for real
         }
         c.done(actions, nil)
         if len(actions) == 0 {
                 return 5 // some arbitrary non-zero number, unlikely to show up on errors
         }
         return 0
 }
@@ skipping 1357 matching lines @@
 // subcommand invocations look more natural.
 //
 // Compare:
 //   * Default: cipd set-ref -ref=abc -version=def package/name
 //   * Improved: cipd set-ref package/name -ref=abc -version=def
 //
 // Much better.
 func Main(params Parameters, args []string) int {
         return subcommands.Run(GetApplication(params), fixFlagsPosition(args))
 }