abort on error and fix debug

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)

api/client/commands.go

@@ -167,8 +167,9 @@ func (cli *DockerCli) CmdBuild(args ...string) error {
 		options := &archive.TarOptions{
 			Compression: archive.Uncompressed,
 		}
-		ignoreFile := path.Join(root, ".dockerignore")
-		if ignore, err := ioutil.ReadFile(ignoreFile); err == nil {
+		if ignore, err := ioutil.ReadFile(path.Join(root, ".dockerignore")); err != nil && !os.IsNotExist(err) {
+			return fmt.Errorf("Error reading .dockerignore: '%s'", err)
+		} else if err == nil {
 			for _, pattern := range strings.Split(string(ignore), "\n") {
 				ok, err := filepath.Match(pattern, "Dockerfile")
 				if err != nil {

archive/archive.go

@@ -343,11 +343,11 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
 				for _, exclude := range options.Excludes {
 					matched, err := filepath.Match(exclude, relFilePath)
 					if err != nil {
-						utils.Errorf("Error matching: %s (pattern: %s)\n", relFilePath, exclude)
+						utils.Errorf("Error matching: %s (pattern: %s)", relFilePath, exclude)
 						return err
 					}
 					if matched {
-						utils.Debugf("Skipping excluded path: %s\n", relFilePath)
+						utils.Debugf("Skipping excluded path: %s", relFilePath)
 						if f.IsDir() {
 							return filepath.SkipDir
 						}