fix stacktrace logging

commands/commands.go

@@ -256,7 +256,11 @@ func logPanicToWriter(w io.Writer, loggedError error) {
 	w.Write(ErrorBuffer.Bytes())
 	fmt.Fprintln(w)
 
-	fmt.Fprintf(w, "%+v\n", loggedError)
+	fmt.Fprintf(w, "%s\n", loggedError)
+	for _, stackline := range errors.StackTrace(loggedError) {
+		fmt.Fprintln(w, stackline)
+	}
+
 	for key, val := range errors.ErrorContext(err) {
 		fmt.Fprintf(w, "%s=%v\n", key, val)
 	}

errors/errors.go

@@ -83,3 +83,20 @@ func Wrapf(err error, format string, args ...interface{}) error {
 
 	return newWrappedError(err, message)
 }
+
+func StackTrace(err error) []string {
+	type stacktrace interface {
+		StackTrace() errors.StackTrace
+	}
+
+	if err, ok := err.(stacktrace); ok {
+		frames := err.StackTrace()
+		lines := make([]string, len(frames))
+		for i, f := range frames {
+			lines[i] = fmt.Sprintf("%+v", f)
+		}
+		return lines
+	}
+
+	return nil
+}