history: add error sources to json output for inspect

Signed-off-by: CrazyMax <[email protected]>

Author: crazy-max

commands/history/inspect.go

@@ -116,6 +116,7 @@ type errorOutput struct {
 	Message string   `json:"message,omitempty"`
 	Name    string   `json:"name,omitempty"`
 	Logs    []string `json:"logs,omitempty"`
+	Sources []byte   `json:"sources,omitempty"`
 
 	statusErr error
 }
@@ -315,6 +316,12 @@ workers0:
 				return errors.Wrapf(err, "failed to unmarshal external error %s", rec.ExternalError.Digest)
 			}
 			out.Error.statusErr = grpcerrors.FromGRPC(status.ErrorProto(&st))
+			var errsources bytes.Buffer
+			for _, s := range errdefs.Sources(out.Error.statusErr) {
+				s.Print(&errsources)
+				errsources.WriteString("\n")
+			}
+			out.Error.Sources = errsources.Bytes()
 			var ve *errdefs.VertexError
 			if errors.As(out.Error.statusErr, &ve) {
 				dgst, err := digest.Parse(ve.Vertex.Digest)
@@ -566,10 +573,9 @@ workers0:
 	}
 
 	if out.Error != nil {
-		for _, s := range errdefs.Sources(out.Error.statusErr) {
-			s.Print(dockerCli.Out())
+		if out.Error.Sources != nil {
+			fmt.Fprint(dockerCli.Out(), string(out.Error.Sources))
 		}
-		fmt.Fprintln(dockerCli.Out())
 		if len(out.Error.Logs) > 0 {
 			fmt.Fprintln(dockerCli.Out(), "Logs:")
 			fmt.Fprintf(dockerCli.Out(), "> => %s:\n", out.Error.Name)