hgext/blackbox.py

--- a/hgext/blackbox.py	Mon Sep 24 14:46:37 2018 -0700
+++ b/hgext/blackbox.py	Thu Jan 17 09:17:12 2019 -0800
@@ -118,7 +118,6 @@
         date = dateutil.datestr(default, ui.config('blackbox', 'date-format'))
         user = procutil.getuser()
         pid = '%d' % procutil.getpid()
-        rev = '(unknown)'
         changed = ''
         ctx = self._repo[None]
         parents = ctx.parents()