install_binary_tarfile: add retry loop for download

cmake/scripts/install_binary_tarfile.py

@@ -36,19 +36,23 @@ def install_tarfile(urltarfile, prefix, lcgprefix, with_hash=True, with_link=Tru
     sys.exit(1)
 
   print('==== Downloading and installing %s' % urltarfile)
-  try:
-    resp = urllib2.urlopen(urltarfile)
-    tar = tarfile.open(fileobj=resp, mode='r|gz', errorlevel=1)
-    dirname, version = os.path.split(tar.next().name)
-    tar.extractall(path=prefix)
-  except urllib2.HTTPError as detail:
-    print('Error downloading %s : %s' % (urltarfile, detail))
-    sys.exit(1)
-  except tarfile.ReadError as detail:
-    print('Error untaring %s : %s' %(urltarfile, detail))
-    sys.exit(1)
-  except:
-    print('Unexpected error:', sys.exc_info()[0])
+  counter = 0
+  success = False
+  while counter < 5 and not success:
+    counter += 1
+    try:
+      resp = urllib2.urlopen(urltarfile)
+      tar = tarfile.open(fileobj=resp, mode='r|gz', errorlevel=1)
+      dirname, version = os.path.split(tar.next().name)
+      tar.extractall(path=prefix)
+      success = True
+    except urllib2.HTTPError as detail:
+      print('Error downloading %s : %s' % (urltarfile, detail))
+    except tarfile.ReadError as detail:
+      print('Error untaring %s : %s' %(urltarfile, detail))
+    except:
+      print('Unexpected error:', sys.exc_info()[0])
+  if not success:
     sys.exit(1)
 
   #---rename the version directory----------------------------------------------