Add a --unmanaged flag to gclient config to allow the main solution to be unmanaged by the scm.

gclient_scm.py

 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Gclient-specific SCM-specific operations."""
 
 import logging
 import os
 import posixpath
 import re
@@ skipping 156 matching lines @@
     """
     if args:
       raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
 
     self._CheckMinVersion("1.6.6")
 
     default_rev = "refs/heads/master"
     url, deps_revision = gclient_utils.SplitUrlRevision(self.url)
     rev_str = ""
     revision = deps_revision
+    managed = True
     if options.revision:
       # Override the revision number.
       revision = str(options.revision)
+    if revision == 'unmanaged':
+      revision = None
+      managed = False
     if not revision:
       revision = default_rev
 
     if gclient_utils.IsDateRevision(revision):
       # Date-revisions only work on git-repositories if the reflog hasn't
       # expired yet. Use rev-list to get the corresponding revision.
       #  git rev-list -n 1 --before='time-stamp' branchname
       if options.transitive:
         print('Warning: --transitive only works for SVN repositories.')
         revision = default_rev
@@ skipping 21 matching lines @@
     if not os.path.exists(self.checkout_path):
       self._Clone(revision, url, options)
       files = self._Capture(['ls-files']).splitlines()
       file_list.extend([os.path.join(self.checkout_path, f) for f in files])
       if not verbose:
         # Make the output a little prettier. It's nice to have some whitespace
         # between projects when cloning.
         print('')
       return
 
+    if not managed:
+      print ('________ unmanaged solution; skipping %s' % self.relpath)
+      return
+
     if not os.path.exists(os.path.join(self.checkout_path, '.git')):
       raise gclient_utils.Error('\n____ %s%s\n'
                                 '\tPath is not a git repo. No .git dir.\n'
                                 '\tTo resolve:\n'
                                 '\t\trm -rf %s\n'
                                 '\tAnd run gclient sync again\n'
                                 % (self.relpath, rev_str, self.relpath))
 
     # See if the url has changed (the unittests use git://foo for the url, let
     # that through).
@@ skipping 497 matching lines @@
       return
 
     if args:
       raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
 
     # revision is the revision to match. It is None if no revision is specified,
     # i.e. the 'deps ain't pinned'.
     url, revision = gclient_utils.SplitUrlRevision(self.url)
     # Keep the original unpinned url for reference in case the repo is switched.
     base_url = url
+    managed = True
     if options.revision:
       # Override the revision number.
       revision = str(options.revision)
     if revision:
-      forced_revision = True
-      # Reconstruct the url.
-      url = '%s@%s' % (url, revision)
-      rev_str = ' at %s' % revision
+      if revision != 'unmanaged':
+        forced_revision = True
+        # Reconstruct the url.
+        url = '%s@%s' % (url, revision)
+        rev_str = ' at %s' % revision
+      else:
+        managed = False
+        revision = None
     else:
       forced_revision = False
       rev_str = ''
 
     if not os.path.exists(self.checkout_path):
       # We need to checkout.
       command = ['checkout', url, self.checkout_path]
       command = self._AddAdditionalUpdateFlags(command, options, revision)
       self._RunAndGetFileList(command, options, file_list, self._root_dir)
       return
 
+    if not managed:
+      print ('________ unmanaged solution; skipping %s' % self.relpath)
+      return
+
     # Get the existing scm url and the revision number of the current checkout.
     try:
       from_info = scm.SVN.CaptureInfo(os.path.join(self.checkout_path, '.'))
     except (gclient_utils.Error, subprocess2.CalledProcessError):
       raise gclient_utils.Error(
           ('Can\'t update/checkout %s if an unversioned directory is present. '
            'Delete the directory and try again.') % self.checkout_path)
 
     # Look for locked directories.
     dir_info = scm.SVN.CaptureStatus(os.path.join(self.checkout_path, '.'))
@@ skipping 172 matching lines @@
 
     This method returns a new list to be used as a command."""
     new_command = command[:]
     if revision:
       new_command.extend(['--revision', str(revision).strip()])
     # --force was added to 'svn update' in svn 1.5.
     if ((options.force or options.manually_grab_svn_rev) and
         scm.SVN.AssertVersion("1.5")[0]):
       new_command.append('--force')
     return new_command