Get original xml when failing to decode

(go newbie here)
I have some code like this:

func (c *clientImpl) queryHost(qtype string, page int) (io.ReadCloser, error) {
	queryURI := c.URL + "/api/query"
	req, _ := http.NewRequest(http.MethodGet, queryURI, nil)
	req.Header.Add(authHeaderName, authToken)
	req.Header.Add("Accept", accept)

	q := req.URL.Query()
	q.Add("type", qtype)
	q.Add("pageSize", pageSize)
	q.Add("page", strconv.Itoa(page))
	req.URL.RawQuery = q.Encode()
	resp, err := c.client.Do(req) //*http.Client
	if err != nil {
		return nil, utils.NestedError("Error in querying Host", err)
	}

	return resp.Body, nil
}

And then called like this:

body, err := c.queryHost(myQType, i)
		if err != nil {
			log.Printf("Error while trying to get page %v - %v \n", i, err)
			return err
		}
		defer body.Close()

		var qResult myQueryResult
		err = xml.NewDecoder(body).Decode(&myQueryResult)
		if err != nil {
			log.Printf("Error while decoding page %v - %v \n", i, err)
			return utils.NestedError("Error in decoding response body xml", err)
		}

I want to log the original xml that was failed to be processed, but since this is a ReadCloser and once read, it cannot be read again (or am I wrong?). Is there a way I can get this, or do I have to store the initial response somewhere and pass copies around?

1. Read bytes with io/ioutil ReadAll

   defer body.Close()

   data, err := ioutil.ReadAll(body)

2. Then unmarshal

   err = xml.Unmarshal(data, &qResult)

You can log data for checking original xml.

For http responses you can use the httputil package's DumpResponse:

Example from the link:

package main

import (
	"fmt"
	"log"
	"net/http"
	"net/http/httptest"
	"net/http/httputil"
)

func main() {
	const body = "Go is a general-purpose language designed with systems programming in mind."
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Date", "Wed, 19 Jul 1972 19:00:00 GMT")
		fmt.Fprintln(w, body)
	}))
	defer ts.Close()

	resp, err := http.Get(ts.URL)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()

	dump, err := httputil.DumpResponse(resp, true)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%q", dump)

}