@@ -142,6 +142,8 @@ GetOSVersion() {

 # be owned by the installation user, we create the directory and change the

 # ownership to the proper user.

 # Set global RECLONE=yes to simulate a clone when dest-dir exists

+# Set global ERROR_ON_CLONE=True to abort execution with an error if the git repo

+# does not exist (default is False, meaning the repo will be cloned).

 # git_clone remote dest-dir branch

 function git_clone {

     [[ "$OFFLINE" = "True" ]] && return

@@ -153,6 +155,7 @@ function git_clone {

     if echo $GIT_BRANCH | egrep -q "^refs"; then

         # If our branch name is a gerrit style refs/changes/...

         if [[ ! -d $GIT_DEST ]]; then

+            [[ "$ERROR_ON_CLONE" = "True" ]] && exit 1

             git clone $GIT_REMOTE $GIT_DEST

         fi

         cd $GIT_DEST

@@ -160,6 +163,7 @@ function git_clone {

     else

         # do a full clone only if the directory doesn't exist

         if [[ ! -d $GIT_DEST ]]; then

+            [[ "$ERROR_ON_CLONE" = "True" ]] && exit 1

             git clone $GIT_REMOTE $GIT_DEST

             cd $GIT_DEST

             # This checkout syntax works for both branches and tags

@@ -214,6 +214,11 @@ fi

 # prerequisites and initialize ``$DEST``.

 OFFLINE=`trueorfalse False $OFFLINE`

+# Set True to configure ``stack.sh`` to exit with an error code if it is asked

+# to clone any git repositories.  If devstack is used in a testing environment,

+# this may be used to ensure that the correct code is being tested.

+ERROR_ON_CLONE=`trueorfalse False $ERROR_ON_CLONE`

+

 # Destination path for service data

 DATA_DIR=${DATA_DIR:-${DEST}/data}

 sudo mkdir -p $DATA_DIR