Update updategit script.

.updater/updategit.py

 
 import fileinput
 import re
+import subprocess
+import sys
 from os import close, remove, path
 from shutil import move
-from subprocess import call
 from tempfile import mkstemp
 
 assert path.isdir('.git'), "No git dir found"
 
+
 def replace(file_path, pattern, subst):
     # From http://stackoverflow.com/a/39110
     fh, abs_path = mkstemp()
     remove(file_path)
     move(abs_path, file_path)
 
+
+def call(args):
+    print('>>> %s' % ' '.join(args))
+    return subprocess.call(args)
+
 call(['git', 'fetch'])
 
+updated = False
 for line in fileinput.input():
     branch, version, changelog, url = line.strip().split(' ')
     branch = 'master' if branch == 'latest' else branch
     call(['git', 'branch', branch, 'master']) # Will fail if the branch exists
     call(['git', 'checkout', branch])
-    call(['git', 'rebase', 'origin/%s' % branch]) # May fail as well
+    call(['git', 'reset', '--hard', 'origin/%s' % branch]) # May fail as well
     replace('Dockerfile', r'^ARG url=.*', 'ARG url=%s' % url)
-    call(['git', 'commit', '-am', 'Auto update to version %s.\n\nChangelog: %s' % (version, changelog)])
-    call(['git', 'push', 'origin', branch])
+    c = call(['git', 'commit', '-am', 'Auto update to version %s.\n\nChangelog: %s' % (version, changelog)])
+    if c == 0:
+      call(['git', 'push', 'origin', branch])
+      updated = True
 
 call(['git', 'checkout', 'master'])
+
+sys.exit(0 if updated else 1)
+