improve version printing when run from a checkout

lib/cdist/__init__.py

@@ -19,7 +19,17 @@
 #
 #
 
-VERSION     = "2.0.9"
+import os
+import subprocess
+
+try:
+    with open(os.devnull, 'w') as devnull:
+        here = os.path.dirname(os.path.realpath(__file__))
+        VERSION = subprocess.check_output(
+                    'cd "%s" && git describe' % here,
+                    stderr=devnull, shell=True).decode('utf-8')
+except:
+    VERSION     = "2.0.9"
 
 BANNER = """
              ..          .       .x+=:.        s
@@ -38,8 +48,6 @@ BANNER = """
 DOT_CDIST   = ".cdist"
 
 
-import os
-
 class Error(Exception):
     """Base exception class for this project"""
     pass