--- a/testing/xpcshell/remotexpcshelltests.py
+++ b/testing/xpcshell/remotexpcshelltests.py
@@ -66,17 +66,17 @@ class XPCShellRemote(xpcshell.XPCShellTe
         self.appRoot = None
         packageName = None
         if self.options.localAPK:
             try:
                 packageName = subprocess.check_output(["unzip", "-p", self.options.localAPK, "package-name.txt"])
                 if packageName:
                     self.appRoot = self.device.getAppRoot(packageName.strip())
             except Exception as detail:
-                print "unable to determine app root: " + detail
+                print "unable to determine app root: " + str(detail)
                 pass
         return None
 
     def remoteJoin(self, path1, path2):
         joined = os.path.join(path1, path2)
         joined = joined.replace('\\', '/')
         return joined