--- a/hgext/evolve.py	Mon Jan 23 16:09:16 2017 +0100
+++ b/hgext/evolve.py	Wed Jan 25 16:50:19 2017 +0100
@@ -3133,7 +3133,10 @@
     else:
         raise error.Abort(_('must specify either --from or --exact'))
 
-    if len(revs) == 1:
+    if not revs:
+        raise error.Abort(_('specified revisions evaluate to an empty set'),
+                          hint=_('use different revision arguments'))
+    elif len(revs) == 1:
         ui.write_err(_('single revision specified, nothing to fold\n'))
         return 1