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

milo/build_source/buildbucket/builder.go

 // Copyright 2016 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
 
 import (
         "encoding/json"
         "fmt"
         "net/url"
         "os"
         "path"
         "path/filepath"
         "strconv"
         "strings"
         "time"
 
         "golang.org/x/net/context"
         "google.golang.org/api/googleapi"
 
         "github.com/luci/gae/service/info"
         "github.com/luci/luci-go/common/api/buildbucket/buildbucket/v1"
         "github.com/luci/luci-go/common/clock"
         "github.com/luci/luci-go/common/errors"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/common/retry"
+        "github.com/luci/luci-go/common/retry/transient"
         "github.com/luci/luci-go/common/sync/parallel"
 
         "github.com/luci/luci-go/milo/api/resp"
         "github.com/luci/luci-go/milo/common"
         "github.com/luci/luci-go/milo/common/model"
 )
 
 // search executes the search request with retries and exponential back-off.
 func search(c context.Context, client *buildbucket.Service, req *buildbucket.SearchCall) (
         *buildbucket.ApiSearchResponseMessage, error) {
 
         var res *buildbucket.ApiSearchResponseMessage
         err := retry.Retry(
                 c,
-                retry.TransientOnly(retry.Default),
+                transient.Only(retry.Default),
                 func() error {
                         var err error
                         res, err = req.Do()
                         if apiErr, ok := err.(*googleapi.Error); ok && apiErr.Code >= 500 {
-                                err = errors.WrapTransient(apiErr)
+                                err = transient.Tag.Apply(apiErr)
                         }
                         return err
                 },
                 func(err error, wait time.Duration) {
                         logging.WithError(err).Warningf(c, "buildbucket search request failed transiently, will retry in %s", wait)
                 })
         return res, err
 }
 
 // fetchBuilds fetches builds given a criteria.
@@ skipping 230 matching lines @@
         return time.Unix(microseconds/1e6, microseconds%1e6*1000).UTC()
 }
 
 type newBuildsFirst []*resp.BuildSummary
 
 func (a newBuildsFirst) Len() int      { return len(a) }
 func (a newBuildsFirst) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
 func (a newBuildsFirst) Less(i, j int) bool {
         return a[i].PendingTime.Started.After(a[j].PendingTime.Started)
 }