Fix typo in source_package.p

lib/webports/source_package.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 contextlib
 import fnmatch
 import os
 import re
 import subprocess
 import sys
@@ skipping 371 matching lines @@
     if self.config.toolchain == 'emscripten':
       util.setup_emscripten()
     env = os.environ.copy()
     env['TOOLCHAIN'] = self.config.toolchain
     env['NACL_ARCH'] = self.config.arch
     env['NACL_DEBUG'] = self.config.debug and '1' or '0'
     env['NACL_SDK_ROOT'] = util.get_sdk_root()
     rtn = subprocess.call(cmd, stdout=sys.stdout, stderr=sys.stderr,
                           cwd=self.root, env=env)
     if rtn != 0:
-      raise Error('Build failed: %s' % self.InfoString())
+      raise Error('Build failed: %s' % self.info_string())
 
   def download(self, force_mirror=None):
     """Download upstream sources and verify integrity."""
     if self.is_git_upstream():
       self.git_clone_to_mirror()
       return
 
     archive = self.download_location()
     if not archive:
       return
@@ skipping 380 matching lines @@
   if os.path.isdir(package_name):
     return SourcePackage(package_name, config)
 
   for subdir in DEFAULT_LOCATIONS:
     pkg_root = os.path.join(paths.NACLPORTS_ROOT, subdir, package_name)
     info = os.path.join(pkg_root, 'pkg_info')
     if os.path.exists(info):
       return SourcePackage(pkg_root, config)
 
   raise Error("Package not found: %s" % package_name)