Convert to using github.com/pkg/errors everywhere

amazonclouddrive/amazonclouddrive.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/rclone/oauthutil"
 	"github.com/ncw/rclone/pacer"
+	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
 	"golang.org/x/oauth2"
 )
@@ -185,7 +186,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 		return f.shouldRetry(resp, err)
 	})
 	if err != nil {
-		return nil, fmt.Errorf("Failed to get endpoints: %v", err)
+		return nil, errors.Wrap(err, "failed to get endpoints")
 	}
 
 	// Get rootID
@@ -195,7 +196,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 		return f.shouldRetry(resp, err)
 	})
 	if err != nil || rootInfo.Id == nil {
-		return nil, fmt.Errorf("Failed to get root: %v", err)
+		return nil, errors.Wrap(err, "failed to get root")
 	}
 
 	f.dirCache = dircache.New(root, *rootInfo.Id, f)
@@ -458,7 +459,7 @@ func (f *Fs) Mkdir() error {
 // refuses to do so if it has anything in
 func (f *Fs) purgeCheck(check bool) error {
 	if f.root == "" {
-		return fmt.Errorf("Can't purge root directory")
+		return errors.New("can't purge root directory")
 	}
 	dc := f.dirCache
 	err := dc.FindRoot(false)
@@ -487,7 +488,7 @@ func (f *Fs) purgeCheck(check bool) error {
 			return err
 		}
 		if !empty {
-			return fmt.Errorf("Directory not empty")
+			return errors.New("directory not empty")
 		}
 	}
 

b2/b2.go

@@ -10,7 +10,6 @@ package b2
 import (
 	"bytes"
 	"crypto/sha1"
-	"errors"
 	"fmt"
 	"hash"
 	"io"
@@ -28,6 +27,7 @@ import (
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/rclone/pacer"
 	"github.com/ncw/rclone/rest"
+	"github.com/pkg/errors"
 )
 
 const (
@@ -119,7 +119,7 @@ var matcher = regexp.MustCompile(`^([^/]*)(.*)$`)
 func parsePath(path string) (bucket, directory string, err error) {
 	parts := matcher.FindStringSubmatch(path)
 	if parts == nil {
-		err = fmt.Errorf("Couldn't find bucket in b2 path %q", path)
+		err = errors.Errorf("couldn't find bucket in b2 path %q", path)
 	} else {
 		bucket, directory = parts[1], parts[2]
 		directory = strings.Trim(directory, "/")
@@ -207,7 +207,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 	}
 	err = f.authorizeAccount()
 	if err != nil {
-		return nil, fmt.Errorf("Failed to authorize account: %v", err)
+		return nil, errors.Wrap(err, "failed to authorize account")
 	}
 	if f.root != "" {
 		f.root += "/"
@@ -247,7 +247,7 @@ func (f *Fs) authorizeAccount() error {
 		return f.shouldRetryNoReauth(resp, err)
 	})
 	if err != nil {
-		return fmt.Errorf("Failed to authenticate: %v", err)
+		return errors.Wrap(err, "failed to authenticate")
 	}
 	f.srv.SetRoot(f.info.APIURL+"/b2api/v1").SetHeader("Authorization", f.info.AuthorizationToken)
 	return nil
@@ -276,7 +276,7 @@ func (f *Fs) getUploadURL() (upload *api.GetUploadURLResponse, err error) {
 			return f.shouldRetryNoReauth(resp, err)
 		})
 		if err != nil {
-			return nil, fmt.Errorf("Failed to get upload URL: %v", err)
+			return nil, errors.Wrap(err, "failed to get upload URL")
 		}
 	} else {
 		upload, f.uploads = f.uploads[0], f.uploads[1:]
@@ -562,7 +562,7 @@ func (f *Fs) getBucketID() (bucketID string, err error) {
 
 	})
 	if bucketID == "" {
-		err = fs.ErrorDirNotFound //fmt.Errorf("Couldn't find bucket %q", f.bucket)
+		err = fs.ErrorDirNotFound
 	}
 	f._bucketID = bucketID
 	return bucketID, err
@@ -618,7 +618,7 @@ func (f *Fs) Mkdir() error {
 				return nil
 			}
 		}
-		return fmt.Errorf("Failed to create bucket: %v", err)
+		return errors.Wrap(err, "failed to create bucket")
 	}
 	f.setBucketID(response.ID)
 	return nil
@@ -649,7 +649,7 @@ func (f *Fs) Rmdir() error {
 		return f.shouldRetry(resp, err)
 	})
 	if err != nil {
-		return fmt.Errorf("Failed to delete bucket: %v", err)
+		return errors.Wrap(err, "failed to delete bucket")
 	}
 	f.clearBucketID()
 	f.clearUploadURL()
@@ -677,7 +677,7 @@ func (f *Fs) deleteByID(ID, Name string) error {
 		return f.shouldRetry(resp, err)
 	})
 	if err != nil {
-		return fmt.Errorf("Failed to delete %q: %v", Name, err)
+		return errors.Wrapf(err, "failed to delete %q", Name)
 	}
 	return nil
 }
@@ -811,7 +811,7 @@ func (o *Object) readMetaData() (err error) {
 		return err
 	}
 	if info == nil {
-		return fmt.Errorf("Object %q not found", o.remote)
+		return errors.Errorf("object %q not found", o.remote)
 	}
 	return o.decodeMetaData(info)
 }
@@ -905,14 +905,14 @@ func (file *openFile) Close() (err error) {
 
 	// Check to see we read the correct number of bytes
 	if file.o.Size() != file.bytes {
-		return fmt.Errorf("Object corrupted on transfer - length mismatch (want %d got %d)", file.o.Size(), file.bytes)
+		return errors.Errorf("object corrupted on transfer - length mismatch (want %d got %d)", file.o.Size(), file.bytes)
 	}
 
 	// Check the SHA1
 	receivedSHA1 := file.resp.Header.Get(sha1Header)
 	calculatedSHA1 := fmt.Sprintf("%x", file.hash.Sum(nil))
 	if receivedSHA1 != calculatedSHA1 {
-		return fmt.Errorf("Object corrupted on transfer - SHA1 mismatch (want %q got %q)", receivedSHA1, calculatedSHA1)
+		return errors.Errorf("object corrupted on transfer - SHA1 mismatch (want %q got %q)", receivedSHA1, calculatedSHA1)
 	}
 
 	return nil
@@ -934,7 +934,7 @@ func (o *Object) Open() (in io.ReadCloser, err error) {
 		return o.fs.shouldRetry(resp, err)
 	})
 	if err != nil {
-		return nil, fmt.Errorf("Failed to open for download: %v", err)
+		return nil, errors.Wrap(err, "failed to open for download")
 	}
 
 	// Parse the time out of the headers if possible
@@ -1015,7 +1015,7 @@ func (o *Object) Update(in io.Reader, src fs.ObjectInfo) (err error) {
 			return err
 		}
 		if n != size {
-			return fmt.Errorf("Read %d bytes expecting %d", n, size)
+			return errors.Errorf("read %d bytes expecting %d", n, size)
 		}
 		calculatedSha1 = fmt.Sprintf("%x", hash.Sum(nil))
 
@@ -1139,7 +1139,7 @@ func (o *Object) Remove() error {
 		return o.fs.shouldRetry(resp, err)
 	})
 	if err != nil {
-		return fmt.Errorf("Failed to delete file: %v", err)
+		return errors.Wrap(err, "failed to delete file")
 	}
 	return nil
 }

dircache/dircache.go

@@ -4,12 +4,12 @@ package dircache
 // _methods are called without the lock
 
 import (
-	"fmt"
 	"log"
 	"strings"
 	"sync"
 
 	"github.com/ncw/rclone/fs"
+	"github.com/pkg/errors"
 )
 
 // DirCache caches paths to directory IDs and vice versa
@@ -159,7 +159,7 @@ func (dc *DirCache) _findDir(path string, create bool) (pathID string, err error
 		if create {
 			pathID, err = dc.fs.CreateDir(parentPathID, leaf)
 			if err != nil {
-				return "", fmt.Errorf("Failed to make directory: %v", err)
+				return "", errors.Wrap(err, "failed to make directory")
 			}
 		} else {
 			return "", fs.ErrorDirNotFound
@@ -240,13 +240,13 @@ func (dc *DirCache) RootParentID() (string, error) {
 	dc.mu.Lock()
 	defer dc.mu.Unlock()
 	if !dc.foundRoot {
-		return "", fmt.Errorf("Internal Error: RootID() called before FindRoot")
+		return "", errors.New("internal error: RootID() called before FindRoot")
 	}
 	if dc.rootParentID == "" {
-		return "", fmt.Errorf("Internal Error: Didn't find rootParentID")
+		return "", errors.New("internal error: didn't find rootParentID")
 	}
 	if dc.rootID == dc.trueRootID {
-		return "", fmt.Errorf("Is root directory")
+		return "", errors.New("is root directory")
 	}
 	return dc.rootParentID, nil
 }

drive/drive.go

@@ -24,6 +24,7 @@ import (
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/rclone/oauthutil"
 	"github.com/ncw/rclone/pacer"
+	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
 )
 
@@ -220,7 +221,7 @@ OUTER:
 			return shouldRetry(err)
 		})
 		if err != nil {
-			return false, fmt.Errorf("Couldn't list directory: %s", err)
+			return false, errors.Wrap(err, "couldn't list directory")
 		}
 		for _, item := range files.Items {
 			if fn(item) {
@@ -253,7 +254,7 @@ func (f *Fs) parseExtensions(extensions string) error {
 	for _, extension := range strings.Split(extensions, ",") {
 		extension = strings.ToLower(strings.TrimSpace(extension))
 		if _, found := extensionToMimeType[extension]; !found {
-			return fmt.Errorf("Couldn't find mime type for extension %q", extension)
+			return errors.Errorf("couldn't find mime type for extension %q", extension)
 		}
 		found := false
 		for _, existingExtension := range f.extensions {
@@ -272,10 +273,10 @@ func (f *Fs) parseExtensions(extensions string) error {
 // NewFs contstructs an Fs from the path, container:path
 func NewFs(name, path string) (fs.Fs, error) {
 	if !isPowerOfTwo(int64(chunkSize)) {
-		return nil, fmt.Errorf("drive: chunk size %v isn't a power of two", chunkSize)
+		return nil, errors.Errorf("drive: chunk size %v isn't a power of two", chunkSize)
 	}
 	if chunkSize < 256*1024 {
-		return nil, fmt.Errorf("drive: chunk size can't be less than 256k - was %v", chunkSize)
+		return nil, errors.Errorf("drive: chunk size can't be less than 256k - was %v", chunkSize)
 	}
 
 	oAuthClient, _, err := oauthutil.NewClient(name, driveConfig)
@@ -298,7 +299,7 @@ func NewFs(name, path string) (fs.Fs, error) {
 	f.client = oAuthClient
 	f.svc, err = drive.New(f.client)
 	if err != nil {
-		return nil, fmt.Errorf("Couldn't create Drive client: %s", err)
+		return nil, errors.Wrap(err, "couldn't create Drive client")
 	}
 
 	// Read About so we know the root path
@@ -307,7 +308,7 @@ func NewFs(name, path string) (fs.Fs, error) {
 		return shouldRetry(err)
 	})
 	if err != nil {
-		return nil, fmt.Errorf("Couldn't read info about Drive: %s", err)
+		return nil, errors.Wrap(err, "couldn't read info about Drive")
 	}
 
 	f.dirCache = dircache.New(root, f.about.RootFolderId, f)
@@ -602,7 +603,7 @@ func (f *Fs) Rmdir() error {
 		return err
 	}
 	if len(children.Items) > 0 {
-		return fmt.Errorf("Directory not empty: %#v", children.Items)
+		return errors.Errorf("directory not empty: %#v", children.Items)
 	}
 	// Delete the directory if it isn't the root
 	if f.root != "" {
@@ -643,7 +644,7 @@ func (f *Fs) Copy(src fs.Object, remote string) (fs.Object, error) {
 		return nil, fs.ErrorCantCopy
 	}
 	if srcObj.isDocument {
-		return nil, fmt.Errorf("Can't copy a Google document")
+		return nil, errors.New("can't copy a Google document")
 	}
 
 	o, createInfo, err := f.createFileInfo(remote, srcObj.ModTime(), srcObj.bytes)
@@ -671,7 +672,7 @@ func (f *Fs) Copy(src fs.Object, remote string) (fs.Object, error) {
 // result of List()
 func (f *Fs) Purge() error {
 	if f.root == "" {
-		return fmt.Errorf("Can't purge root directory")
+		return errors.New("can't purge root directory")
 	}
 	err := f.dirCache.FindRoot(false)
 	if err != nil {
@@ -708,7 +709,7 @@ func (f *Fs) Move(src fs.Object, remote string) (fs.Object, error) {
 		return nil, fs.ErrorCantMove
 	}
 	if srcObj.isDocument {
-		return nil, fmt.Errorf("Can't move a Google document")
+		return nil, errors.New("can't move a Google document")
 	}
 
 	// Temporary FsObject under construction
@@ -857,7 +858,7 @@ func (o *Object) readMetaData() (err error) {
 	}
 	if !found {
 		fs.Debug(o, "Couldn't find object")
-		return fmt.Errorf("Couldn't find object")
+		return errors.New("couldn't find object")
 	}
 	return nil
 }
@@ -914,7 +915,7 @@ func (o *Object) Storable() bool {
 // using the method passed in
 func (o *Object) httpResponse(method string) (res *http.Response, err error) {
 	if o.url == "" {
-		return nil, fmt.Errorf("Forbidden to download - check sharing permission")
+		return nil, errors.New("forbidden to download - check sharing permission")
 	}
 	req, err := http.NewRequest(method, o.url, nil)
 	if err != nil {
@@ -970,7 +971,7 @@ func (o *Object) Open() (in io.ReadCloser, err error) {
 	}
 	if res.StatusCode != 200 {
 		_ = res.Body.Close() // ignore error
-		return nil, fmt.Errorf("Bad response: %d: %s", res.StatusCode, res.Status)
+		return nil, errors.Errorf("bad response: %d: %s", res.StatusCode, res.Status)
 	}
 	// If it is a document, update the size with what we are
 	// reading as it can change from the HEAD in the listing to
@@ -991,7 +992,7 @@ func (o *Object) Update(in io.Reader, src fs.ObjectInfo) error {
 	size := src.Size()
 	modTime := src.ModTime()
 	if o.isDocument {
-		return fmt.Errorf("Can't update a google document")
+		return errors.New("can't update a google document")
 	}
 	updateInfo := &drive.File{
 		Id:           o.id,
@@ -1025,7 +1026,7 @@ func (o *Object) Update(in io.Reader, src fs.ObjectInfo) error {
 // Remove an object
 func (o *Object) Remove() error {
 	if o.isDocument {
-		return fmt.Errorf("Can't delete a google document")
+		return errors.New("can't delete a google document")
 	}
 	var err error
 	err = o.fs.pacer.Call(func() (bool, error) {

drive/drive_internal_test.go

@@ -1,9 +1,9 @@
 package drive
 
 import (
-	"fmt"
 	"testing"
 
+	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"google.golang.org/api/drive/v2"
 )
@@ -17,11 +17,15 @@ func TestInternalParseExtensions(t *testing.T) {
 		{"doc", []string{"doc"}, nil},
 		{" docx ,XLSX, 	pptx,svg", []string{"docx", "xlsx", "pptx", "svg"}, nil},
 		{"docx,svg,Docx", []string{"docx", "svg"}, nil},
-		{"docx,potato,docx", []string{"docx"}, fmt.Errorf(`Couldn't find mime type for extension "potato"`)},
+		{"docx,potato,docx", []string{"docx"}, errors.New(`couldn't find mime type for extension "potato"`)},
 	} {
 		f := new(Fs)
 		gotErr := f.parseExtensions(test.in)
-		assert.Equal(t, test.wantErr, gotErr)
+		if test.wantErr == nil {
+			assert.NoError(t, gotErr)
+		} else {
+			assert.EqualError(t, gotErr, test.wantErr.Error())
+		}
 		assert.Equal(t, test.want, f.extensions)
 	}
 

drive/upload.go

@@ -21,6 +21,7 @@ import (
 	"strconv"
 
 	"github.com/ncw/rclone/fs"
+	"github.com/pkg/errors"
 	"google.golang.org/api/drive/v2"
 	"google.golang.org/api/googleapi"
 )
@@ -138,7 +139,7 @@ func (rx *resumableUpload) transferStatus() (start int64, err error) {
 		if err != nil {
 			return 0, err
 		}
-		return 0, fmt.Errorf("unexpected http return code %v", res.StatusCode)
+		return 0, errors.Errorf("unexpected http return code %v", res.StatusCode)
 	}
 	Range := res.Header.Get("Range")
 	if m := rangeRE.FindStringSubmatch(Range); len(m) == 2 {
@@ -147,7 +148,7 @@ func (rx *resumableUpload) transferStatus() (start int64, err error) {
 			return start, nil
 		}
 	}
-	return 0, fmt.Errorf("unable to parse range %q", Range)
+	return 0, errors.Errorf("unable to parse range %q", Range)
 }
 
 // Transfer a chunk - caller must call googleapi.CloseBody(res) if err == nil || res != nil

dropbox/dropbox.go

@@ -9,7 +9,6 @@ File system is case insensitive
 
 import (
 	"crypto/md5"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -21,6 +20,7 @@ import (
 
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/rclone/oauthutil"
+	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
 	"github.com/stacktic/dropbox"
 )
@@ -148,7 +148,7 @@ func newDropbox(name string) (*dropbox.Dropbox, error) {
 // NewFs contstructs an Fs from the path, container:path
 func NewFs(name, root string) (fs.Fs, error) {
 	if uploadChunkSize > maxUploadChunkSize {
-		return nil, fmt.Errorf("Chunk size too big, must be < %v", maxUploadChunkSize)
+		return nil, errors.Errorf("chunk size too big, must be < %v", maxUploadChunkSize)
 	}
 	db, err := newDropbox(name)
 	if err != nil {
@@ -239,7 +239,7 @@ func strip(path, root string) (string, error) {
 	}
 	lowercase := strings.ToLower(path)
 	if !strings.HasPrefix(lowercase, root) {
-		return "", fmt.Errorf("Path %q is not under root %q", path, root)
+		return "", errors.Errorf("path %q is not under root %q", path, root)
 	}
 	return path[len(root):], nil
 }
@@ -267,11 +267,11 @@ func (f *Fs) list(out fs.ListOpts, dir string) {
 	for {
 		deltaPage, err := f.db.Delta(cursor, root)
 		if err != nil {
-			out.SetError(fmt.Errorf("Couldn't list: %s", err))
+			out.SetError(errors.Wrap(err, "couldn't list"))
 			return
 		}
 		if deltaPage.Reset && cursor != "" {
-			err = errors.New("Unexpected reset during listing")
+			err = errors.New("unexpected reset during listing")
 			out.SetError(err)
 			break
 		}
@@ -368,7 +368,7 @@ func (f *Fs) listOneLevel(out fs.ListOpts, dir string) {
 	}
 	entry, err := f.db.Metadata(root, true, false, "", "", metadataLimit)
 	if err != nil {
-		out.SetError(fmt.Errorf("Couldn't list single level: %s", err))
+		out.SetError(errors.Wrap(err, "couldn't list single level"))
 		return
 	}
 	for i := range entry.Contents {
@@ -448,7 +448,7 @@ func (f *Fs) Mkdir() error {
 		if entry.IsDir {
 			return nil
 		}
-		return fmt.Errorf("%q already exists as file", f.root)
+		return errors.Errorf("%q already exists as file", f.root)
 	}
 	_, err = f.db.CreateFolder(f.slashRoot)
 	return err
@@ -463,7 +463,7 @@ func (f *Fs) Rmdir() error {
 		return err
 	}
 	if len(entry.Contents) != 0 {
-		return errors.New("Directory not empty")
+		return errors.New("directory not empty")
 	}
 	return f.Purge()
 }
@@ -499,7 +499,7 @@ func (f *Fs) Copy(src fs.Object, remote string) (fs.Object, error) {
 	dstPath := dstObj.remotePath()
 	entry, err := f.db.Copy(srcPath, dstPath, false)
 	if err != nil {
-		return nil, fmt.Errorf("Copy failed: %s", err)
+		return nil, errors.Wrap(err, "copy failed")
 	}
 	dstObj.setMetadataFromEntry(entry)
 	return dstObj, nil
@@ -542,7 +542,7 @@ func (f *Fs) Move(src fs.Object, remote string) (fs.Object, error) {
 	dstPath := dstObj.remotePath()
 	entry, err := f.db.Move(srcPath, dstPath)
 	if err != nil {
-		return nil, fmt.Errorf("Move failed: %s", err)
+		return nil, errors.Wrap(err, "move failed")
 	}
 	dstObj.setMetadataFromEntry(entry)
 	return dstObj, nil
@@ -571,7 +571,7 @@ func (f *Fs) DirMove(src fs.Fs) error {
 	// Do the move
 	_, err = f.db.Move(srcFs.slashRoot, f.slashRoot)
 	if err != nil {
-		return fmt.Errorf("MoveDir failed: %v", err)
+		return errors.Wrap(err, "MoveDir failed")
 	}
 	return nil
 }
@@ -625,7 +625,7 @@ func (o *Object) readEntry() (*dropbox.Entry, error) {
 	entry, err := o.fs.db.Metadata(o.remotePath(), false, false, "", "", metadataLimit)
 	if err != nil {
 		fs.Debug(o, "Error reading file: %s", err)
-		return nil, fmt.Errorf("Error reading file: %s", err)
+		return nil, errors.Wrap(err, "error reading file")
 	}
 	return entry, nil
 }
@@ -717,7 +717,7 @@ func (o *Object) Update(in io.Reader, src fs.ObjectInfo) error {
 	}
 	entry, err := o.fs.db.UploadByChunk(ioutil.NopCloser(in), int(uploadChunkSize), remote, true, "")
 	if err != nil {
-		return fmt.Errorf("Upload failed: %s", err)
+		return errors.Wrap(err, "upload failed")
 	}
 	o.setMetadataFromEntry(entry)
 	return nil

fs/buffer.go

@@ -1,8 +1,9 @@
 package fs
 
 import (
-	"fmt"
 	"io"
+
+	"github.com/pkg/errors"
 )
 
 // asyncReader will do async read-ahead from the input reader
@@ -29,13 +30,13 @@ type asyncReader struct {
 // When done use Close to release the buffers and close the supplied input.
 func newAsyncReader(rd io.ReadCloser, buffers, size int) (io.ReadCloser, error) {
 	if size <= 0 {
-		return nil, fmt.Errorf("buffer size too small")
+		return nil, errors.New("buffer size too small")
 	}
 	if buffers <= 0 {
-		return nil, fmt.Errorf("number of buffers too small")
+		return nil, errors.New("number of buffers too small")
 	}
 	if rd == nil {
-		return nil, fmt.Errorf("nil reader supplied")
+		return nil, errors.New("nil reader supplied")
 	}
 	a := &asyncReader{}
 	a.init(rd, buffers, size)

fs/config.go

@@ -26,6 +26,7 @@ import (
 
 	"github.com/Unknwon/goconfig"
 	"github.com/mreiferson/go-httpclient"
+	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
 	"golang.org/x/crypto/nacl/secretbox"
 	"golang.org/x/text/unicode/norm"
@@ -128,7 +129,7 @@ func (x SizeSuffix) String() string {
 // Set a SizeSuffix
 func (x *SizeSuffix) Set(s string) error {
 	if len(s) == 0 {
-		return fmt.Errorf("Empty string")
+		return errors.New("empty string")
 	}
 	if strings.ToLower(s) == "off" {
 		*x = -1
@@ -150,7 +151,7 @@ func (x *SizeSuffix) Set(s string) error {
 	case 'g', 'G':
 		multiplier = 1 << 30
 	default:
-		return fmt.Errorf("Bad suffix %q", suffix)
+		return errors.Errorf("bad suffix %q", suffix)
 	}
 	s = s[:len(s)-suffixLen]
 	value, err := strconv.ParseFloat(s, 64)
@@ -158,7 +159,7 @@ func (x *SizeSuffix) Set(s string) error {
 		return err
 	}
 	if value < 0 {
-		return fmt.Errorf("Size can't be negative %q", s)
+		return errors.Errorf("size can't be negative %q", s)
 	}
 	value *= multiplier
 	*x = SizeSuffix(value)
@@ -402,7 +403,7 @@ func loadConfigFile() (*goconfig.ConfigFile, error) {
 			break
 		}
 		if strings.HasPrefix(l, "RCLONE_ENCRYPT_V") {
-			return nil, fmt.Errorf("Unsupported configuration encryption. Update rclone for support.")
+			return nil, errors.New("unsupported configuration encryption - update rclone for support")
 		}
 		return goconfig.LoadFromReader(bytes.NewBuffer(b))
 	}
@@ -411,10 +412,10 @@ func loadConfigFile() (*goconfig.ConfigFile, error) {
 	dec := base64.NewDecoder(base64.StdEncoding, r)
 	box, err := ioutil.ReadAll(dec)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to load base64 encoded data: %v", err)
+		return nil, errors.Wrap(err, "failed to load base64 encoded data")
 	}
 	if len(box) < 24+secretbox.Overhead {
-		return nil, fmt.Errorf("Configuration data too short")
+		return nil, errors.New("Configuration data too short")
 	}
 	envpw := os.Getenv("RCLONE_CONFIG_PASS")
 
@@ -431,7 +432,7 @@ func loadConfigFile() (*goconfig.ConfigFile, error) {
 		}
 		if len(configKey) == 0 {
 			if !*AskPassword {
-				return nil, fmt.Errorf("Unable to decrypt configuration and not allowed to ask for password. Set RCLONE_CONFIG_PASS to your configuration password.")
+				return nil, errors.New("unable to decrypt configuration and not allowed to ask for password - set RCLONE_CONFIG_PASS to your configuration password")
 			}
 			getPassword("Enter configuration password:")
 		}
@@ -479,7 +480,7 @@ func getPassword(q string) {
 // zero after trimming+normalization, an error is returned.
 func setPassword(password string) error {
 	if !utf8.ValidString(password) {
-		return fmt.Errorf("Password contains invalid utf8 characters")
+		return errors.New("password contains invalid utf8 characters")
 	}
 	// Remove leading+trailing whitespace
 	password = strings.TrimSpace(password)
@@ -487,7 +488,7 @@ func setPassword(password string) error {
 	// Normalize to reduce weird variations.
 	password = norm.NFKC.String(password)
 	if len(password) == 0 {
-		return fmt.Errorf("No characters in password")
+		return errors.New("no characters in password")
 	}
 	// Create SHA256 has of the password
 	sha := sha256.New()

fs/filter.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
 )
 
@@ -227,7 +228,7 @@ func NewFilter() (f *Filter, err error) {
 		}
 		f.ModTimeFrom = time.Now().Add(-duration)
 		if !f.ModTimeTo.IsZero() && f.ModTimeTo.Before(f.ModTimeFrom) {
-			return nil, fmt.Errorf("Argument --min-age can't be larger than --max-age")
+			return nil, errors.New("argument --min-age can't be larger than --max-age")
 		}
 		Debug(nil, "--max-age %v to %v", duration, f.ModTimeFrom)
 	}
@@ -306,7 +307,7 @@ func (f *Filter) AddRule(rule string) error {
 	case strings.HasPrefix(rule, "+ "):
 		return f.Add(true, rule[2:])
 	}
-	return fmt.Errorf("Malformed rule %q", rule)
+	return errors.Errorf("malformed rule %q", rule)
 }
 
 // AddFile adds a single file to the files from list

fs/fs.go

@@ -11,6 +11,8 @@ import (
 	"regexp"
 	"sort"
 	"time"
+
+	"github.com/pkg/errors"
 )
 
 // Constants
@@ -29,17 +31,17 @@ var (
 	// Filesystem registry
 	fsRegistry []*RegInfo
 	// ErrorNotFoundInConfigFile is returned by NewFs if not found in config file
-	ErrorNotFoundInConfigFile = fmt.Errorf("Didn't find section in config file")
+	ErrorNotFoundInConfigFile = errors.New("didn't find section in config file")
-	ErrorCantPurge            = fmt.Errorf("Can't purge directory")
+	ErrorCantPurge            = errors.New("can't purge directory")
-	ErrorCantCopy             = fmt.Errorf("Can't copy object - incompatible remotes")
+	ErrorCantCopy             = errors.New("can't copy object - incompatible remotes")
-	ErrorCantMove             = fmt.Errorf("Can't move object - incompatible remotes")
+	ErrorCantMove             = errors.New("can't move object - incompatible remotes")
-	ErrorCantDirMove          = fmt.Errorf("Can't move directory - incompatible remotes")
+	ErrorCantDirMove          = errors.New("can't move directory - incompatible remotes")
-	ErrorDirExists            = fmt.Errorf("Can't copy directory - destination already exists")
+	ErrorDirExists            = errors.New("can't copy directory - destination already exists")
-	ErrorCantSetModTime       = fmt.Errorf("Can't set modified time")
+	ErrorCantSetModTime       = errors.New("can't set modified time")
-	ErrorDirNotFound          = fmt.Errorf("Directory not found")
+	ErrorDirNotFound          = errors.New("directory not found")
-	ErrorLevelNotSupported    = fmt.Errorf("Level value not supported")
+	ErrorLevelNotSupported    = errors.New("level value not supported")
-	ErrorListAborted          = fmt.Errorf("List aborted")
+	ErrorListAborted          = errors.New("list aborted")
-	ErrorListOnlyRoot         = fmt.Errorf("Can only list from root")
+	ErrorListOnlyRoot         = errors.New("can only list from root")
 )
 
 // RegInfo provides information about a filesystem
@@ -323,7 +325,7 @@ func Find(name string) (*RegInfo, error) {
 			return item, nil
 		}
 	}
-	return nil, fmt.Errorf("Didn't find filing system for %q", name)
+	return nil, errors.Errorf("didn't find filing system for %q", name)
 }
 
 // Pattern to match an rclone url

fs/glob.go

@@ -4,9 +4,10 @@ package fs
 
 import (
 	"bytes"
-	"fmt"
 	"regexp"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 // globToRegexp converts an rsync style glob to a regexp
@@ -29,7 +30,7 @@ func globToRegexp(glob string) (*regexp.Regexp, error) {
 			case 2:
 				_, _ = re.WriteString(`.*`)
 			default:
-				return fmt.Errorf("too many stars in %q", glob)
+				return errors.Errorf("too many stars in %q", glob)
 			}
 		}
 		consecutiveStars = 0
@@ -72,16 +73,16 @@ func globToRegexp(glob string) (*regexp.Regexp, error) {
 			_, _ = re.WriteRune(c)
 			inBrackets++
 		case ']':
-			return nil, fmt.Errorf("mismatched ']' in glob %q", glob)
+			return nil, errors.Errorf("mismatched ']' in glob %q", glob)
 		case '{':
 			if inBraces {
-				return nil, fmt.Errorf("can't nest '{' '}' in glob %q", glob)
+				return nil, errors.Errorf("can't nest '{' '}' in glob %q", glob)
 			}
 			inBraces = true
 			_, _ = re.WriteRune('(')
 		case '}':
 			if !inBraces {
-				return nil, fmt.Errorf("mismatched '{' and '}' in glob %q", glob)
+				return nil, errors.Errorf("mismatched '{' and '}' in glob %q", glob)
 			}
 			_, _ = re.WriteRune(')')
 			inBraces = false
@@ -103,15 +104,15 @@ func globToRegexp(glob string) (*regexp.Regexp, error) {
 		return nil, err
 	}
 	if inBrackets > 0 {
-		return nil, fmt.Errorf("mismatched '[' and ']' in glob %q", glob)
+		return nil, errors.Errorf("mismatched '[' and ']' in glob %q", glob)
 	}
 	if inBraces {
-		return nil, fmt.Errorf("mismatched '{' and '}' in glob %q", glob)
+		return nil, errors.Errorf("mismatched '{' and '}' in glob %q", glob)
 	}
 	_, _ = re.WriteRune('$')
 	result, err := regexp.Compile(re.String())
 	if err != nil {
-		return nil, fmt.Errorf("Bad glob pattern %q: %v (%q)", glob, err, re.String())
+		return nil, errors.Wrapf(err, "bad glob pattern %q (regexp %q)", glob, re.String())
 	}
 	return result, nil
 }

fs/glob_test.go

@@ -37,7 +37,7 @@ func TestGlobToRegexp(t *testing.T) {
 		{`ab}c`, `(^|/)`, `mismatched '{' and '}'`},
 		{`ab{c`, `(^|/)`, `mismatched '{' and '}'`},
 		{`*.{jpg,png,gif}`, `(^|/)[^/]*\.(jpg|png|gif)$`, ``},
-		{`[a--b]`, `(^|/)`, `Bad glob pattern`},
+		{`[a--b]`, `(^|/)`, `bad glob pattern`},
 		{`a\*b`, `(^|/)a\*b$`, ``},
 		{`a\\b`, `(^|/)a\\b$`, ``},
 	} {

fs/hash.go

@@ -8,6 +8,8 @@ import (
 	"hash"
 	"io"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 // HashType indicates a standard hashing algorithm
@@ -15,7 +17,7 @@ type HashType int
 
 // ErrHashUnsupported should be returned by filesystem,
 // if it is requested to deliver an unsupported hash type.
-var ErrHashUnsupported = fmt.Errorf("hash type not supported")
+var ErrHashUnsupported = errors.New("hash type not supported")
 
 const (
 	// HashMD5 indicates MD5 support
@@ -82,7 +84,7 @@ func (h HashType) String() string {
 // and this function must support all types.
 func hashFromTypes(set HashSet) (map[HashType]hash.Hash, error) {
 	if !set.SubsetOf(SupportedHashes) {
-		return nil, fmt.Errorf("Requested set %08x contains unknown hash types", int(set))
+		return nil, errors.Errorf("requested set %08x contains unknown hash types", int(set))
 	}
 	var hashers = make(map[HashType]hash.Hash)
 	types := set.Array()

fs/limited.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"io"
 	"time"
+
+	"github.com/pkg/errors"
 )
 
 // Limited defines a Fs which can only return the Objects passed in
@@ -70,7 +72,7 @@ func (f *Limited) Put(in io.Reader, src ObjectInfo) (Object, error) {
 	remote := src.Remote()
 	obj := f.NewFsObject(remote)
 	if obj == nil {
-		return nil, fmt.Errorf("Can't create %q in limited fs", remote)
+		return nil, errors.Errorf("can't create %q in limited fs", remote)
 	}
 	return obj, obj.Update(in, src)
 }

fs/lister_test.go

@@ -1,11 +1,11 @@
 package fs
 
 import (
-	"errors"
 	"io"
 	"testing"
 	"time"
 
+	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -17,7 +17,7 @@ func TestListerNew(t *testing.T) {
 	assert.Equal(t, MaxLevel, o.level)
 }
 
-var errNotImpl = errors.New("Not implemented")
+var errNotImpl = errors.New("not implemented")
 
 type mockObject string
 

fs/operations.go

@@ -14,6 +14,8 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/pkg/errors"
+
 	"golang.org/x/text/unicode/norm"
 )
 
@@ -261,7 +263,7 @@ tryAgain:
 	// Verify sizes are the same after transfer
 	if src.Size() != dst.Size() {
 		Stats.Error()
-		err = fmt.Errorf("Corrupted on transfer: sizes differ %d vs %d", src.Size(), dst.Size())
+		err = errors.Errorf("corrupted on transfer: sizes differ %d vs %d", src.Size(), dst.Size())
 		ErrorLog(dst, "%s", err)
 		removeFailedCopy(dst)
 		return
@@ -287,7 +289,7 @@ tryAgain:
 				ErrorLog(dst, "Failed to read hash: %s", err)
 			} else if !HashEquals(srcSum, dstSum) {
 				Stats.Error()
-				err = fmt.Errorf("Corrupted on transfer: %v hash differ %q vs %q", hashType, srcSum, dstSum)
+				err = errors.Errorf("corrupted on transfer: %v hash differ %q vs %q", hashType, srcSum, dstSum)
 				ErrorLog(dst, "%s", err)
 				removeFailedCopy(dst)
 				return
@@ -796,7 +798,7 @@ func Check(fdst, fsrc Fs) error {
 	checkerWg.Wait()
 	Log(fdst, "%d differences found", Stats.GetErrors())
 	if differences > 0 {
-		return fmt.Errorf("%d differences found", differences)
+		return errors.Errorf("%d differences found", differences)
 	}
 	return nil
 }

googlecloudstorage/googlecloudstorage.go

@@ -15,7 +15,6 @@ FIXME Patch/Delete/Get isn't working with files with spaces in - giving 404 erro
 import (
 	"encoding/base64"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -27,13 +26,13 @@ import (
 	"strings"
 	"time"
 
+	"github.com/ncw/rclone/fs"
+	"github.com/ncw/rclone/oauthutil"
+	"github.com/pkg/errors"
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 	"google.golang.org/api/googleapi"
 	"google.golang.org/api/storage/v1"
-
-	"github.com/ncw/rclone/fs"
-	"github.com/ncw/rclone/oauthutil"
 )
 
 const (
@@ -182,7 +181,7 @@ var matcher = regexp.MustCompile(`^([^/]*)(.*)$`)
 func parsePath(path string) (bucket, directory string, err error) {
 	parts := matcher.FindStringSubmatch(path)
 	if parts == nil {
-		err = fmt.Errorf("Couldn't find bucket in storage path %q", path)
+		err = errors.Errorf("couldn't find bucket in storage path %q", path)
 	} else {
 		bucket, directory = parts[1], parts[2]
 		directory = strings.Trim(directory, "/")
@@ -193,11 +192,11 @@ func parsePath(path string) (bucket, directory string, err error) {
 func getServiceAccountClient(keyJsonfilePath string) (*http.Client, error) {
 	data, err := ioutil.ReadFile(os.ExpandEnv(keyJsonfilePath))
 	if err != nil {
-		return nil, fmt.Errorf("error opening credentials file: %v", err)
+		return nil, errors.Wrap(err, "error opening credentials file")
 	}
 	conf, err := google.JWTConfigFromJSON(data, storageConfig.Scopes...)
 	if err != nil {
-		return nil, fmt.Errorf("error processing credentials: %v", err)
+		return nil, errors.Wrap(err, "error processing credentials")
 	}
 	ctxWithSpecialClient := oauthutil.Context()
 	return oauth2.NewClient(ctxWithSpecialClient, conf.TokenSource(ctxWithSpecialClient)), nil
@@ -245,7 +244,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 	f.client = oAuthClient
 	f.svc, err = storage.New(f.client)
 	if err != nil {
-		return nil, fmt.Errorf("Couldn't create Google Cloud Storage client: %s", err)
+		return nil, errors.Wrap(err, "couldn't create Google Cloud Storage client")
 	}
 
 	if f.root != "" {
@@ -357,7 +356,7 @@ func (f *Fs) list(dir string, level int, fn listFn) error {
 func (f *Fs) listFiles(out fs.ListOpts, dir string) {
 	defer out.Finished()
 	if f.bucket == "" {
-		out.SetError(fmt.Errorf("Can't list objects at root - choose a bucket using lsd"))
+		out.SetError(errors.New("can't list objects at root - choose a bucket using lsd"))
 		return
 	}
 	// List the objects
@@ -398,7 +397,7 @@ func (f *Fs) listBuckets(out fs.ListOpts, dir string) {
 		return
 	}
 	if f.projectNumber == "" {
-		out.SetError(errors.New("Can't list buckets without project number"))
+		out.SetError(errors.New("can't list buckets without project number"))
 		return
 	}
 	listBuckets := f.svc.Buckets.List(f.projectNumber).MaxResults(listChunks)
@@ -458,7 +457,7 @@ func (f *Fs) Mkdir() error {
 	}
 
 	if f.projectNumber == "" {
-		return fmt.Errorf("Can't make bucket without project number")
+		return errors.New("can't make bucket without project number")
 	}
 
 	bucket := storage.Bucket{
@@ -670,7 +669,7 @@ func (o *Object) Open() (in io.ReadCloser, err error) {
 	}
 	if res.StatusCode != 200 {
 		_ = res.Body.Close() // ignore error
-		return nil, fmt.Errorf("Bad response: %d: %s", res.StatusCode, res.Status)
+		return nil, errors.Errorf("bad response: %d: %s", res.StatusCode, res.Status)
 	}
 	return res.Body, nil
 }

hubic/hubic.go

@@ -17,6 +17,7 @@ import (
 	"github.com/ncw/rclone/oauthutil"
 	"github.com/ncw/rclone/swift"
 	swiftLib "github.com/ncw/swift"
+	"github.com/pkg/errors"
 	"golang.org/x/oauth2"
 )
 
@@ -118,7 +119,7 @@ func (f *Fs) getCredentials() (err error) {
 	}
 	defer fs.CheckClose(resp.Body, &err)
 	if resp.StatusCode < 200 || resp.StatusCode > 299 {
-		return fmt.Errorf("Failed to get credentials: %s", resp.Status)
+		return errors.Errorf("failed to get credentials: %s", resp.Status)
 	}
 	decoder := json.NewDecoder(resp.Body)
 	var result credentials
@@ -128,7 +129,7 @@ func (f *Fs) getCredentials() (err error) {
 	}
 	// fs.Debug(f, "Got credentials %+v", result)
 	if result.Token == "" || result.Endpoint == "" || result.Expires == "" {
-		return fmt.Errorf("Couldn't read token, result and expired from credentials")
+		return errors.New("couldn't read token, result and expired from credentials")
 	}
 	f.credentials = result
 	expires, err := time.Parse(time.RFC3339, result.Expires)
@@ -144,7 +145,7 @@ func (f *Fs) getCredentials() (err error) {
 func NewFs(name, root string) (fs.Fs, error) {
 	client, _, err := oauthutil.NewClient(name, oauthConfig)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to configure Hubic: %v", err)
+		return nil, errors.Wrap(err, "failed to configure Hubic")
 	}
 
 	f := &Fs{
@@ -161,7 +162,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 	}
 	err = c.Authenticate()
 	if err != nil {
-		return nil, fmt.Errorf("Error authenticating swift connection: %v", err)
+		return nil, errors.Wrap(err, "error authenticating swift connection")
 	}
 
 	// Make inner swift Fs from the connection

local/local.go

@@ -80,7 +80,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 		f.root, remote = getDirFile(f.root)
 		obj := f.NewFsObject(remote)
 		if obj == nil {
-			return nil, fmt.Errorf("Failed to make object for %q in %q", remote, f.root)
+			return nil, errors.Errorf("failed to make object for %q in %q", remote, f.root)
 		}
 		// return a Fs Limited to this object
 		return fs.NewLimited(f, obj), nil
@@ -368,7 +368,7 @@ func (f *Fs) Purge() error {
 		return err
 	}
 	if !fi.Mode().IsDir() {
-		return fmt.Errorf("Can't Purge non directory: %q", f.root)
+		return errors.Errorf("can't purge non directory: %q", f.root)
 	}
 	return os.RemoveAll(f.root)
 }
@@ -400,7 +400,7 @@ func (f *Fs) Move(src fs.Object, remote string) (fs.Object, error) {
 		return nil, err
 	} else if !dstObj.info.Mode().IsRegular() {
 		// It isn't a file
-		return nil, fmt.Errorf("Can't move file onto non-file")
+		return nil, errors.New("can't move file onto non-file")
 	}
 
 	// Create destination
@@ -490,7 +490,7 @@ func (o *Object) Hash(r fs.HashType) (string, error) {
 	oldsize := o.info.Size()
 	err := o.lstat()
 	if err != nil {
-		return "", errors.Wrap(err, "Hash failed to stat")
+		return "", errors.Wrap(err, "hash: failed to stat")
 	}
 
 	if !o.info.ModTime().Equal(oldtime) || oldsize != o.info.Size() {
@@ -501,15 +501,15 @@ func (o *Object) Hash(r fs.HashType) (string, error) {
 		o.hashes = make(map[fs.HashType]string)
 		in, err := os.Open(o.path)
 		if err != nil {
-			return "", errors.Wrap(err, "Hash failed to open")
+			return "", errors.Wrap(err, "hash: failed to open")
 		}
 		o.hashes, err = fs.HashStream(in)
 		closeErr := in.Close()
 		if err != nil {
-			return "", errors.Wrap(err, "Hash failed to read")
+			return "", errors.Wrap(err, "hash: failed to read")
 		}
 		if closeErr != nil {
-			return "", errors.Wrap(closeErr, "Hash failed to close")
+			return "", errors.Wrap(closeErr, "hash: failed to close")
 		}
 	}
 	return o.hashes[r], nil

oauthutil/oauthutil.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/ncw/rclone/fs"
+	"github.com/pkg/errors"
 	"github.com/skratchdot/open-golang/open"
 	"golang.org/x/net/context"
 	"golang.org/x/oauth2"
@@ -58,7 +59,7 @@ func getToken(name string) (*oauth2.Token, error) {
 		return nil, err
 	}
 	if tokenString == "" {
-		return nil, fmt.Errorf("Empty token found - please run rclone config again")
+		return nil, errors.New("empty token found - please run rclone config again")
 	}
 	token := new(oauth2.Token)
 	err = json.Unmarshal([]byte(tokenString), token)
@@ -301,7 +302,7 @@ func Config(id, name string, config *oauth2.Config) error {
 		if authCode != "" {
 			fmt.Printf("Got code\n")
 		} else {
-			return fmt.Errorf("Failed to get code")
+			return errors.New("failed to get code")
 		}
 	} else {
 		// Read the code, and exchange it for a token.
@@ -310,14 +311,14 @@ func Config(id, name string, config *oauth2.Config) error {
 	}
 	token, err := config.Exchange(oauth2.NoContext, authCode)
 	if err != nil {
-		return fmt.Errorf("Failed to get token: %v", err)
+		return errors.Wrap(err, "failed to get token")
 	}
 
 	// Print code if we do automatic retrieval
 	if automatic {
 		result, err := json.Marshal(token)
 		if err != nil {
-			return fmt.Errorf("Failed to marshal token: %v", err)
+			return errors.Wrap(err, "failed to marshal token")
 		}
 		fmt.Printf("Paste the following into your remote machine --->\n%s\n<---End paste", result)
 	}

onedrive/onedrive.go

@@ -187,7 +187,7 @@ func NewFs(name, root string) (fs.Fs, error) {
 	// Get rootID
 	rootInfo, _, err := f.readMetaDataForPath("")
 	if err != nil || rootInfo.ID == "" {
-		return nil, fmt.Errorf("Failed to get root: %v", err)
+		return nil, errors.Wrap(err, "failed to get root")
 	}
 
 	f.dirCache = dircache.New(root, rootInfo.ID, f)
@@ -258,7 +258,7 @@ func (f *Fs) FindLeaf(pathID, leaf string) (pathIDOut string, found bool, err er
 	// fs.Debug(f, "FindLeaf(%q, %q)", pathID, leaf)
 	parent, ok := f.dirCache.GetInv(pathID)
 	if !ok {
-		return "", false, fmt.Errorf("Couldn't find parent ID")
+		return "", false, errors.New("couldn't find parent ID")
 	}
 	path := leaf
 	if parent != "" {
@@ -275,7 +275,7 @@ func (f *Fs) FindLeaf(pathID, leaf string) (pathIDOut string, found bool, err er
 		return "", false, err
 	}
 	if info.Folder == nil {
-		return "", false, fmt.Errorf("Found file when looking for folder")
+		return "", false, errors.New("found file when looking for folder")
 	}
 	return info.ID, true, nil
 }
@@ -467,7 +467,7 @@ func (f *Fs) deleteObject(id string) error {
 // refuses to do so if it has anything in
 func (f *Fs) purgeCheck(check bool) error {
 	if f.root == "" {
-		return fmt.Errorf("Can't purge root directory")
+		return errors.New("can't purge root directory")
 	}
 	dc := f.dirCache
 	err := dc.FindRoot(false)
@@ -480,10 +480,10 @@ func (f *Fs) purgeCheck(check bool) error {
 		return err
 	}
 	if item.Folder == nil {
-		return fmt.Errorf("Not a folder")
+		return errors.New("not a folder")
 	}
 	if check && item.Folder.ChildCount != 0 {
-		return fmt.Errorf("Folder not empty")
+		return errors.New("folder not empty")
 	}
 	err = f.deleteObject(rootID)
 	if err != nil {
@@ -533,7 +533,7 @@ func (f *Fs) waitForJob(location string, o *Object) error {
 				return err
 			}
 			if status.Status == "failed" || status.Status == "deleteFailed" {
-				return fmt.Errorf("Async operation %q returned %q", status.Operation, status.Status)
+				return errors.Errorf("async operation %q returned %q", status.Operation, status.Status)
 			}
 		} else {
 			var info api.Item
@@ -546,7 +546,7 @@ func (f *Fs) waitForJob(location string, o *Object) error {
 		}
 		time.Sleep(1 * time.Second)
 	}
-	return fmt.Errorf("Async operation didn't complete after %v", fs.Config.Timeout)
+	return errors.Errorf("async operation didn't complete after %v", fs.Config.Timeout)
 }
 
 // Copy src to this remote using server side copy operations.
@@ -601,7 +601,7 @@ func (f *Fs) Copy(src fs.Object, remote string) (fs.Object, error) {
 	// read location header
 	location := resp.Header.Get("Location")
 	if location == "" {
-		return nil, fmt.Errorf("Didn't receive location header in copy response")
+		return nil, errors.New("didn't receive location header in copy response")
 	}
 
 	// Wait for job to finish
@@ -764,7 +764,7 @@ func (o *Object) Storable() bool {
 // Open an object for read
 func (o *Object) Open() (in io.ReadCloser, err error) {
 	if o.id == "" {
-		return nil, fmt.Errorf("Can't download no id")
+		return nil, errors.New("can't download - no id")
 	}
 	var resp *http.Response
 	opts := rest.Opts{
@@ -834,7 +834,7 @@ func (o *Object) cancelUploadSession(url string) (err error) {
 // uploadMultipart uploads a file using multipart upload
 func (o *Object) uploadMultipart(in io.Reader, size int64) (err error) {
 	if chunkSize%(320*1024) != 0 {
-		return fmt.Errorf("Chunk size %d is not a multiple of 320k", chunkSize)
+		return errors.Errorf("chunk size %d is not a multiple of 320k", chunkSize)
 	}
 
 	// Create upload session

pacer/pacer_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/ncw/rclone/fs"
+	"github.com/pkg/errors"
 )
 
 func TestNew(t *testing.T) {
@@ -310,7 +311,7 @@ func TestEndCallZeroConnections(t *testing.T) {
 	}
 }
 
-var errFoo = fmt.Errorf("Foo")
+var errFoo = errors.New("foo")
 
 type dummyPaced struct {
 	retry  bool

rest/rest.go

@@ -6,13 +6,13 @@ package rest
 import (
 	"bytes"
 	"encoding/json"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"sync"
 
 	"github.com/ncw/rclone/fs"
+	"github.com/pkg/errors"
 )
 
 // Client contains the info to sustain the API
@@ -43,7 +43,7 @@ func defaultErrorHandler(resp *http.Response) (err error) {
 	if err != nil {
 		return err
 	}
-	return fmt.Errorf("HTTP error %v (%v) returned body: %q", resp.StatusCode, resp.Status, body)
+	return errors.Errorf("HTTP error %v (%v) returned body: %q", resp.StatusCode, resp.Status, body)
 }
 
 // SetErrorHandler sets the handler to decode an error response when
@@ -102,14 +102,14 @@ func (api *Client) Call(opts *Opts) (resp *http.Response, err error) {
 	api.mu.RLock()
 	defer api.mu.RUnlock()
 	if opts == nil {
-		return nil, fmt.Errorf("call() called with nil opts")
+		return nil, errors.New("call() called with nil opts")
 	}
 	var url string
 	if opts.Absolute {
 		url = opts.Path
 	} else {
 		if api.rootURL == "" {
-			return nil, fmt.Errorf("RootURL not set")
+			return nil, errors.New("RootURL not set")
 		}
 		url = api.rootURL + opts.Path
 	}

s3/s3.go

@@ -14,7 +14,6 @@ What happens if you CTRL-C a multipart upload
 */
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -36,6 +35,7 @@ import (
 	"github.com/aws/aws-sdk-go/service/s3/s3manager"
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/swift"
+	"github.com/pkg/errors"
 )
 
 // Register with Fs
@@ -200,7 +200,7 @@ var matcher = regexp.MustCompile(`^([^/]*)(.*)$`)
 func s3ParsePath(path string) (bucket, directory string, err error) {
 	parts := matcher.FindStringSubmatch(path)
 	if parts == nil {
-		err = fmt.Errorf("Couldn't parse bucket out of s3 path %q", path)
+		err = errors.Errorf("couldn't parse bucket out of s3 path %q", path)
 	} else {
 		bucket, directory = parts[1], parts[2]
 		directory = strings.Trim(directory, "/")
@@ -452,7 +452,7 @@ func (f *Fs) listFiles(out fs.ListOpts, dir string) {
 	defer out.Finished()
 	if f.bucket == "" {
 		// Return no objects at top level list
-		out.SetError(errors.New("Can't list objects at root - choose a bucket using lsd"))
+		out.SetError(errors.New("can't list objects at root - choose a bucket using lsd"))
 		return
 	}
 	// List the objects and directories

swift/swift.go

@@ -3,7 +3,6 @@ package swift
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"io"
 	"path"
@@ -14,6 +13,7 @@ import (
 
 	"github.com/ncw/rclone/fs"
 	"github.com/ncw/swift"
+	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
 )
 
@@ -132,7 +132,7 @@ var matcher = regexp.MustCompile(`^([^/]*)(.*)$`)
 func parsePath(path string) (container, directory string, err error) {
 	parts := matcher.FindStringSubmatch(path)
 	if parts == nil {
-		err = fmt.Errorf("Couldn't find container in swift path %q", path)
+		err = errors.Errorf("couldn't find container in swift path %q", path)
 	} else {
 		container, directory = parts[1], parts[2]
 		directory = strings.Trim(directory, "/")
@@ -318,7 +318,7 @@ func (f *Fs) list(dir string, level int, fn listFn) error {
 func (f *Fs) listFiles(out fs.ListOpts, dir string) {
 	defer out.Finished()
 	if f.container == "" {
-		out.SetError(errors.New("Can't list objects at root - choose a container using lsd"))
+		out.SetError(errors.New("can't list objects at root - choose a container using lsd"))
 		return
 	}
 	// List the objects

yandex/api/client.go

@@ -2,13 +2,14 @@ package src
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 //Client struct

yandex/api/performdelete.go

@@ -1,9 +1,10 @@
 package src
 
 import (
-	"fmt"
 	"io/ioutil"
 	"net/http"
+
+	"github.com/pkg/errors"
 )
 
 // PerformDelete does the actual delete via DELETE request.
@@ -28,7 +29,7 @@ func (c *Client) PerformDelete(url string) error {
 		if err != nil {
 			return err
 		}
-		return fmt.Errorf("delete error [%d]: %s", resp.StatusCode, string(body[:]))
+		return errors.Errorf("delete error [%d]: %s", resp.StatusCode, string(body[:]))
 	}
 	return nil
 }

yandex/api/performdownload.go

@@ -1,10 +1,11 @@
 package src
 
 import (
-	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
+
+	"github.com/pkg/errors"
 )
 
 // PerformDownload does the actual download via unscoped PUT request.
@@ -27,7 +28,7 @@ func (c *Client) PerformDownload(url string) (out io.ReadCloser, err error) {
 		if err != nil {
 			return nil, err
 		}
-		return nil, fmt.Errorf("download error [%d]: %s", resp.StatusCode, string(body[:]))
+		return nil, errors.Errorf("download error [%d]: %s", resp.StatusCode, string(body[:]))
 	}
 	return resp.Body, err
 }

yandex/api/performmkdir.go

@@ -1,9 +1,10 @@
 package src
 
 import (
-	"fmt"
 	"io/ioutil"
 	"net/http"
+
+	"github.com/pkg/errors"
 )
 
 // PerformMkdir does the actual mkdir via PUT request.
@@ -27,7 +28,7 @@ func (c *Client) PerformMkdir(url string) (int, string, error) {
 			return 0, "", err
 		}
 		//third parameter is the json error response body
-		return resp.StatusCode, string(body[:]), fmt.Errorf("Create Folder error [%d]: %s", resp.StatusCode, string(body[:]))
+		return resp.StatusCode, string(body[:]), errors.Errorf("create folder error [%d]: %s", resp.StatusCode, string(body[:]))
 	}
 	return resp.StatusCode, "", nil
 }

yandex/api/performupload.go

@@ -3,10 +3,11 @@ package src
 //from yadisk
 
 import (
-	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
+
+	"github.com/pkg/errors"
 )
 
 // PerformUpload does the actual upload via unscoped PUT request.
@@ -30,7 +31,7 @@ func (c *Client) PerformUpload(url string, data io.Reader) (err error) {
 			return err
 		}
 
-		return fmt.Errorf("upload error [%d]: %s", resp.StatusCode, string(body[:]))
+		return errors.Errorf("upload error [%d]: %s", resp.StatusCode, string(body[:]))
 	}
 	return nil
 }

yandex/yandex.go

@@ -407,10 +407,10 @@ func (f *Fs) purgeCheck(check bool) error {
 		var opt yandex.ResourceInfoRequestOptions
 		ResourceInfoResponse, err := f.yd.NewResourceInfoRequest(f.diskRoot, opt).Exec()
 		if err != nil {
-			return fmt.Errorf("Rmdir failed: %s", err)
+			return errors.Wrap(err, "rmdir failed")
 		}
 		if len(ResourceInfoResponse.Embedded.Items) != 0 {
-			return fmt.Errorf("Rmdir failed: Directory not empty")
+			return errors.New("rmdir failed: directory not empty")
 		}
 	}
 	//delete directory