diff --git a/puppet/modules/devstack/files/git_clone.sh b/puppet/modules/devstack/files/git_clone.sh
index 7434f6a..485978a 100755
--- a/puppet/modules/devstack/files/git_clone.sh
+++ b/puppet/modules/devstack/files/git_clone.sh
@@ -7,7 +7,7 @@
 # git_update_branch ref
 function git_update_branch {
 
-    GIT_BRANCH=$1
+    local GIT_BRANCH=$1
 
     git checkout -f origin/$GIT_BRANCH
     # a local branch might not exist
@@ -19,7 +19,7 @@ function git_update_branch {
 # git_update_remote_branch ref
 function git_update_remote_branch {
 
-    GIT_BRANCH=$1
+    local GIT_BRANCH=$1
 
     git checkout -b $GIT_BRANCH -t origin/$GIT_BRANCH
 }
@@ -29,7 +29,7 @@ function git_update_remote_branch {
 # git_update_tag ref
 function git_update_tag {
 
-    GIT_TAG=$1
+    local GIT_TAG=$1
 
     git tag -d $GIT_TAG
     # fetching given tag only
@@ -42,9 +42,9 @@ function git_update_tag {
 # ownership to the proper user.
 # git_clone remote dest-dir branch
 function git_clone {
-    GIT_REMOTE=$1
-    GIT_DEST=$2
-    GIT_REF=$3
+    local GIT_REMOTE=$1
+    local GIT_DEST=$2
+    local GIT_REF=$3
 
     # do a full clone only if the directory doesn't exist
     if [[ ! -d $GIT_DEST ]]; then
@@ -115,4 +115,7 @@ URL=${1:-https://github.com/openstack-dev/devstack}
 BRANCH=${2:-master}
 LOCAL=${3:-/home/stack/devstack}
 
+set -o xtrace
+set -o errexit
+
 git_clone $URL $LOCAL $BRANCH
diff --git a/puppet/modules/devstack/manifests/init.pp b/puppet/modules/devstack/manifests/init.pp
index de741b3..2bef4a6 100644
--- a/puppet/modules/devstack/manifests/init.pp
+++ b/puppet/modules/devstack/manifests/init.pp
@@ -29,7 +29,7 @@ class devstack(
     environment => "HOME=/home/$user",
     user => 'stack',
     group => 'stack',
-    command => "/usr/local/bin/git_clone.sh $devstack_git $devstack_branch $dir",
+    command => "/usr/local/bin/git_clone.sh ${source} ${branch} ${dir}",
     logoutput => true,
     timeout => 1200
   }