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

scheduler/appengine/task/buildbucket/buildbucket.go

 // Copyright 2015 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 buildbucket implements tasks that run Buildbucket jobs.
 package buildbucket
 
 import (
         "encoding/json"
         "fmt"
         "net/url"
         "time"
 
         "github.com/golang/protobuf/proto"
         "golang.org/x/net/context"
         "google.golang.org/api/pubsub/v1"
 
         "github.com/luci/gae/service/info"
         "github.com/luci/luci-go/common/api/buildbucket/buildbucket/v1"
         "github.com/luci/luci-go/common/errors"
+        "github.com/luci/luci-go/common/retry/transient"
         "github.com/luci/luci-go/scheduler/appengine/messages"
         "github.com/luci/luci-go/scheduler/appengine/task"
         "github.com/luci/luci-go/scheduler/appengine/task/utils"
 )
 
 const (
         statusCheckTimerName     = "check-buildbucket-build-status"
         statusCheckTimerInterval = time.Minute
 )
 
@@ skipping 258 matching lines @@
         }
 }
 
 func (m TaskManager) checkBuildStatus(c context.Context, ctl task.Controller) error {
         switch status := ctl.State().Status; {
         // This can happen if Buildbucket manages to send PubSub message before
         // LaunchTask finishes. Do not touch State or DebugLog to avoid collision with
         // still running LaunchTask when saving the invocation, it will only make the
         // matters worse.
         case status == task.StatusStarting:
-                return errors.WrapTransient(errors.New("invocation is still starting, try again later"))
+                return errors.New("invocation is still starting, try again later", transient.Tag)
         case status != task.StatusRunning:
                 return fmt.Errorf("unexpected invocation status %q, expecting %q", status, task.StatusRunning)
         }
 
         // Grab build ID from the blob generated in LaunchTask.
         taskData := taskData{}
         if err := json.Unmarshal(ctl.State().TaskData, &taskData); err != nil {
                 ctl.State().Status = task.StatusFailed
                 return fmt.Errorf("could not parse TaskData - %s", err)
         }
 
         // Fetch build result from Buildbucket.
         service, err := m.createBuildbucketService(c, ctl)
         if err != nil {
                 return err
         }
         resp, err := service.Get(taskData.BuildID).Do()
         if err != nil {
                 ctl.DebugLog("Failed to fetch buildbucket build - %s", err)
                 err = utils.WrapAPIError(err)
-                if !errors.IsTransient(err) {
+                if !transient.Tag.In(err) {
                         ctl.State().Status = task.StatusFailed
                 }
                 return err
         }
 
         // Dump response in full to the debug log. It doesn't contain any secrets.
         blob, err := json.MarshalIndent(resp, "", "  ")
         if err != nil {
                 return err
         }
@@ skipping 28 matching lines @@
                 r.Id, r.Status, r.Result, r.FailureReason, r.CancelationReason)
         switch {
         case r.Status == "SCHEDULED" || r.Status == "STARTED":
                 return // do nothing
         case r.Status == "COMPLETED" && r.Result == "SUCCESS":
                 ctl.State().Status = task.StatusSucceeded
         default:
                 ctl.State().Status = task.StatusFailed
         }
 }