Remove github.com/pkg/errors and replace with std library version

This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.

This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.

backend/yandex/yandex.go

@@ -3,6 +3,7 @@ package yandex
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -13,7 +14,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/pkg/errors"
 	"github.com/rclone/rclone/backend/yandex/api"
 	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/config"
@@ -249,7 +249,7 @@ func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, e
 
 	token, err := oauthutil.GetToken(name, m)
 	if err != nil {
-		return nil, errors.Wrap(err, "couldn't read OAuth token")
+		return nil, fmt.Errorf("couldn't read OAuth token: %w", err)
 	}
 	if token.RefreshToken == "" {
 		return nil, errors.New("unable to get RefreshToken. If you are upgrading from older versions of rclone, please run `rclone config` and re-configure this backend")
@@ -258,13 +258,13 @@ func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, e
 		token.TokenType = "OAuth"
 		err = oauthutil.PutToken(name, m, token, false)
 		if err != nil {
-			return nil, errors.Wrap(err, "couldn't save OAuth token")
+			return nil, fmt.Errorf("couldn't save OAuth token: %w", err)
 		}
 		log.Printf("Automatically upgraded OAuth config.")
 	}
 	oAuthClient, _, err := oauthutil.NewClient(ctx, name, m, oauthConfig)
 	if err != nil {
-		return nil, errors.Wrap(err, "failed to configure Yandex")
+		return nil, fmt.Errorf("failed to configure Yandex: %w", err)
 	}
 
 	ci := fs.GetConfig(ctx)
@@ -309,7 +309,7 @@ func (f *Fs) itemToDirEntry(ctx context.Context, remote string, object *api.Reso
 	case "dir":
 		t, err := time.Parse(time.RFC3339Nano, object.Modified)
 		if err != nil {
-			return nil, errors.Wrap(err, "error parsing time in directory item")
+			return nil, fmt.Errorf("error parsing time in directory item: %w", err)
 		}
 		d := fs.NewDir(remote, t).SetSize(object.Size)
 		return d, nil
@@ -560,19 +560,19 @@ func (f *Fs) waitForJob(ctx context.Context, location string) (err error) {
 		var status api.AsyncStatus
 		err = json.Unmarshal(body, &status)
 		if err != nil {
-			return errors.Wrapf(err, "async status result not JSON: %q", body)
+			return fmt.Errorf("async status result not JSON: %q: %w", body, err)
 		}
 
 		switch status.Status {
 		case "failure":
-			return errors.Errorf("async operation returned %q", status.Status)
+			return fmt.Errorf("async operation returned %q", status.Status)
 		case "success":
 			return nil
 		}
 
 		time.Sleep(1 * time.Second)
 	}
-	return errors.Errorf("async operation didn't complete after %v", f.ci.TimeoutOrInfinite())
+	return fmt.Errorf("async operation didn't complete after %v", f.ci.TimeoutOrInfinite())
 }
 
 func (f *Fs) delete(ctx context.Context, path string, hardDelete bool) (err error) {
@@ -607,7 +607,7 @@ func (f *Fs) delete(ctx context.Context, path string, hardDelete bool) (err erro
 		var info api.AsyncInfo
 		err = json.Unmarshal(body, &info)
 		if err != nil {
-			return errors.Wrapf(err, "async info result not JSON: %q", body)
+			return fmt.Errorf("async info result not JSON: %q: %w", body, err)
 		}
 		return f.waitForJob(ctx, info.HRef)
 	}
@@ -623,7 +623,7 @@ func (f *Fs) purgeCheck(ctx context.Context, dir string, check bool) error {
 		//send request to get list of objects in this directory.
 		info, err := f.readMetaDataForPath(ctx, root, &api.ResourceInfoRequestOptions{})
 		if err != nil {
-			return errors.Wrap(err, "rmdir failed")
+			return fmt.Errorf("rmdir failed: %w", err)
 		}
 		if len(info.Embedded.Items) != 0 {
 			return fs.ErrorDirectoryNotEmpty
@@ -683,7 +683,7 @@ func (f *Fs) copyOrMove(ctx context.Context, method, src, dst string, overwrite
 		var info api.AsyncInfo
 		err = json.Unmarshal(body, &info)
 		if err != nil {
-			return errors.Wrapf(err, "async info result not JSON: %q", body)
+			return fmt.Errorf("async info result not JSON: %q: %w", body, err)
 		}
 		return f.waitForJob(ctx, info.HRef)
 	}
@@ -714,7 +714,7 @@ func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (fs.Object,
 	err = f.copyOrMove(ctx, "copy", srcObj.filePath(), dstPath, false)
 
 	if err != nil {
-		return nil, errors.Wrap(err, "couldn't copy file")
+		return nil, fmt.Errorf("couldn't copy file: %w", err)
 	}
 
 	return f.NewObject(ctx, remote)
@@ -744,7 +744,7 @@ func (f *Fs) Move(ctx context.Context, src fs.Object, remote string) (fs.Object,
 	err = f.copyOrMove(ctx, "move", srcObj.filePath(), dstPath, false)
 
 	if err != nil {
-		return nil, errors.Wrap(err, "couldn't move file")
+		return nil, fmt.Errorf("couldn't move file: %w", err)
 	}
 
 	return f.NewObject(ctx, remote)
@@ -795,7 +795,7 @@ func (f *Fs) DirMove(ctx context.Context, src fs.Fs, srcRemote, dstRemote string
 	err = f.copyOrMove(ctx, "move", srcPath, dstPath, false)
 
 	if err != nil {
-		return errors.Wrap(err, "couldn't move directory")
+		return fmt.Errorf("couldn't move directory: %w", err)
 	}
 	return nil
 }
@@ -831,9 +831,9 @@ func (f *Fs) PublicLink(ctx context.Context, remote string, expire fs.Duration,
 	}
 	if err != nil {
 		if unlink {
-			return "", errors.Wrap(err, "couldn't remove public link")
+			return "", fmt.Errorf("couldn't remove public link: %w", err)
 		}
-		return "", errors.Wrap(err, "couldn't create public link")
+		return "", fmt.Errorf("couldn't create public link: %w", err)
 	}
 
 	info, err := f.readMetaDataForPath(ctx, f.filePath(remote), &api.ResourceInfoRequestOptions{})
@@ -934,7 +934,7 @@ func (o *Object) setMetaData(info *api.ResourceInfoResponse) (err error) {
 	}
 	t, err := time.Parse(time.RFC3339Nano, modTimeString)
 	if err != nil {
-		return errors.Wrapf(err, "failed to parse modtime from %q", modTimeString)
+		return fmt.Errorf("failed to parse modtime from %q: %w", modTimeString, err)
 	}
 	o.modTime = t
 	return nil