handle bad python install

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 2c83c8138ea8acab45b2219bce1f45cbb2241cd7..c19e96309793f2c7c40edbffd2050f6358ec0d84 100644
--- a/gclient.py
+++ b/gclient.py
@@ -1719,6 +1719,10 @@ def Main(argv):
         '\nYour python version %s is unsupported, please upgrade.\n' %
         sys.version.split(' ', 1)[0])
     return 2
+  if not sys.executable:
+    print >> sys.stderr, (
+        '\nPython cannot find the location of it\'s own executable.\n')
+    return 2
   colorama.init()
   try:
     # Make stdout auto-flush so buildbot doesn't kill us during lengthy