diff --git a/pkg/httputil/httputil.go b/pkg/httputil/httputil.go
index <HASH>..<HASH> 100644
--- a/pkg/httputil/httputil.go
+++ b/pkg/httputil/httputil.go
@@ -27,6 +27,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"path"
 	"strconv"
 	"strings"
@@ -63,7 +64,7 @@ func RequestEntityTooLargeError(conn http.ResponseWriter) {
 
 func ServeError(conn http.ResponseWriter, req *http.Request, err error) {
 	conn.WriteHeader(http.StatusInternalServerError)
-	if IsLocalhost(req) {
+	if IsLocalhost(req) || os.Getenv("CAMLI_DEV_CAMLI_ROOT") != "" {
 		fmt.Fprintf(conn, "Server error: %s\n", err)
 		return
 	}
httputil: allow full error serving when with devcam

When hacking on e.g. importers, I sometimes want to use devcam with
-hostname, to test with a non local context. In which case, when hitting
an error httputil.ServeError would not print the full error, which
makes it harder to debug.

Change-Id: I2fb8c<I>d4f<I>fbf<I>addd6e7af<I>