Switch devenv to use pkg packages

lib/naclports/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 os
 
 from naclports.util import Log, Warn, LogVerbose
 from naclports.error import Error
 from naclports import configuration, pkg_info, util
 
@@ skipping 133 matching lines @@
     self.config = configuration.Configuration(self.BUILD_ARCH,
                                               self.BUILD_TOOLCHAIN,
                                               self.BUILD_CONFIG == 'debug')
 
   def Uninstall(self):
     self.LogStatus('Uninstalling')
     self.DoUninstall()
 
   def Files(self):
     """Yields the list of files currently installed by this package."""
+    file_list = self.GetListFile()
+    if not os.path.exists(file_list):
+      return
     with open(self.GetListFile()) as f:
       for line in f:
         yield line.strip()
 
   def DoUninstall(self):
     with util.InstallLock(self.config):
       RemoveFile(self.GetInstallStamp())
 
       root = util.GetInstallRoot(self.config)
       for filename in self.Files():
         fullname = os.path.join(root, filename)
         if not os.path.lexists(fullname):
           Warn('File not found while uninstalling: %s' % fullname)
           continue
         LogVerbose('uninstall: %s' % filename)
         RemoveFile(fullname)
 
-      RemoveFile(self.GetListFile())
+      if os.path.exists(self.GetListFile()):
+        RemoveFile(self.GetListFile())
 
 
 def InstalledPackageIterator(config):
   stamp_root = util.GetInstallStampRoot(config)
   if not os.path.exists(stamp_root):
     return
 
   for filename in os.listdir(stamp_root):
     if os.path.splitext(filename)[1] != '.info':
       continue
     yield InstalledPackage(os.path.join(stamp_root, filename))
 
 
 def CreateInstalledPackage(package_name, config=None):
   stamp_root = util.GetInstallStampRoot(config)
   info_file = os.path.join(stamp_root, package_name + '.info')
   if not os.path.exists(info_file):
     raise Error('package not installed: %s [%s]' % (package_name, config))
   return InstalledPackage(info_file)