Call `git submodule sync` to update upstream URL's, if necessary.

git-crup

 #!/bin/sh
 # Copyright (c) 2012 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.
 
 # A convenience script to largely replicate the behavior of `gclient sync` in a
 # submodule-based checkout.  Fetches latest commits for top-level solutions;
 # updates submodules; and runs post-sync hooks.
 
 j=10
 ECHO=
 pull=pull
 pull_args=
 hooks=yes
 
 usage() {
   cat <<EOF 1>&2
 Usage: git-cr-sync [-n|--dry-run] [--fetch] [-j|--jobs [jobs]]
     [--no-hooks] [<args to git-pull or git-fetch>]
 EOF
 }
 
 parallel_update() {
-  ( echo Entering "$1" &&
-    cd "$1" &&
-    $ECHO git $pull $pull_args origin &&
-    git ls-files -s | grep ^160000 | awk '{print $4}' |
-    xargs -L 1 -P "$j" $ECHO git submodule update --init )
+  ( echo Entering "$1"
+    cd "$1"
+    $ECHO git $pull $pull_args origin
+    $ECHO git submodule sync
+    if ( echo test | xargs --max-lines=1 true 2>/dev/null ); then
+      max_lines="--max-lines=1"
+    else
+      max_lines="-L 1"
+    fi
+    if ( echo test | xargs -P "$j" true 2>/dev/null )
+    then
+      git ls-files -s | grep ^160000 | awk '{print $4}' |
+      xargs $max_lines -P "$j" $ECHO git submodule update --init
+    else
+      echo "Warn: parallel execution is not supported on this platform."
+      $ECHO git submodule update --init
+    fi )
 }
 
 while test $# -ne 0; do
   case "$1" in
     -j|--jobs)
       if test -n "$2"; then
         j="$2"
         shift
       else
         j=0
@@ skipping 29 matching lines @@
 if test "$PWD" = "/"; then
   echo "Could not find the root of your checkout; aborting." 1>&2
   exit 1
 fi
 
 ls -d */.git |
 while read gitdir; do
   parallel_update `dirname $gitdir`
 done
 
-test "$hooks" = "yes" && test -x src/.git/hooks/deps2hooks.sh &&
-src/.git/hooks/deps2hooks.sh
-
+gclient_spec="solutions=[{'name':'src','url':None,'deps_file':'.DEPS.git'}]"
+test "$hooks" = "yes" && gclient runhooks --spec="$gclient_spec"