Improve tracing/logging system used in lib/naclports

lib/naclports/package_index.py

 # Copyright (c) 2014 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 
 from naclports import configuration, binary_package, package, util, paths
 from naclports import pkg_info, error
 
 DEFAULT_INDEX = os.path.join(paths.NACLPORTS_ROOT, 'lib', 'prebuilt.txt')
@@ skipping 66 matching lines @@
     return (package_name, config) in self.packages
 
   def Installable(self, package_name, config):
     """Returns True if the index contains the given package and it is
     installable in the currently configured SDK."""
     info = self.packages.get((package_name, config))
     if not info:
       return False
     version = util.GetSDKVersion()
     if info['BUILD_SDK_VERSION'] != version:
-      util.Trace('Prebuilt package was built with different SDK version: '
-                 '%s vs %s' % (info['BUILD_SDK_VERSION'], version))
+      util.LogVerbose('Prebuilt package was built with different SDK version: '
+                      '%s vs %s' % (info['BUILD_SDK_VERSION'], version))
       return False
     return True
 
   def Download(self, package_name, config):
     if not os.path.exists(PREBUILT_ROOT):
       util.Makedirs(PREBUILT_ROOT)
     info = self.packages[(package_name, config)]
     filename = os.path.join(PREBUILT_ROOT, os.path.basename(info['BIN_URL']))
     if os.path.exists(filename):
       try:
@@ skipping 14 matching lines @@
       info = pkg_info.ParsePkgInfo(info_files, self.filename,
                                    self.valid_keys, self.required_keys)
       debug = info['BUILD_CONFIG'] == 'debug'
       config = configuration.Configuration(info['BUILD_ARCH'],
                                            info['BUILD_TOOLCHAIN'],
                                            debug)
       key = (info['NAME'], config)
       if key in self.packages:
         error.Error('package index contains duplicate: %s' % str(key))
       self.packages[key] = info