diff -r 000000000000 -r 6474c204b198 testing/xpcshell/b2g_xpcshell_venv.sh
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/xpcshell/b2g_xpcshell_venv.sh	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,63 @@
+#!/bin/bash
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+PYTHON=$1
+
+if [ -z "${PYTHON}" ]
+then
+    echo "No python found"
+    exit 1
+fi
+
+if [ -z "${MARIONETTE_HOME}" ]
+then
+    echo "No MARIONETTE_HOME found"
+    exit 1
+fi
+
+if [ -z "${XPCSHELLTEST_HOME}" ]
+then
+    echo "No XPCSHELLTEST_HOME found"
+    exit 1
+fi
+
+echo "Detected Marionette home in $MARIONETTE_HOME"
+
+# If a GECKO_OBJDIR environemnt variable exists, we will create the Python
+# virtual envirnoment there. Otherwise we create it in the PWD.
+VENV_DIR="marionette_venv"
+if [ -z $GECKO_OBJDIR ]
+then
+    VENV_DIR="$MARIONETTE_HOME/$VENV_DIR"
+else
+    VENV_DIR="$GECKO_OBJDIR/$VENV_DIR"
+fi
+
+# Check if environment exists, if not, create a virtualenv:
+if [ -d $VENV_DIR ]
+then
+  echo "Using virtual environment in $VENV_DIR"
+  cd $VENV_DIR
+  . bin/activate
+else
+  echo "Creating a virtual environment in $VENV_DIR"
+  curl https://raw.github.com/pypa/virtualenv/develop/virtualenv.py | ${PYTHON} - $VENV_DIR
+  cd $VENV_DIR
+  . bin/activate
+  # set up mozbase
+  git clone git://github.com/mozilla/mozbase.git
+  cd mozbase
+  python setup_development.py
+fi
+
+# update the marionette_client
+cd $MARIONETTE_HOME
+python setup.py develop
+
+cd $XPCSHELLTEST_HOME
+
+# pop off the python parameter
+shift
+python runtestsb2g.py $@