--- a/hgext3rd/evolve/state.py	Thu Jul 11 14:21:23 2019 -0700
+++ b/hgext3rd/evolve/state.py	Thu Jul 11 16:49:01 2019 -0700
@@ -45,6 +45,8 @@
     def __nonzero__(self):
         return self.exists()
 
+    __bool__ = __nonzero__
+
     def __contains__(self, key):
         return key in self.opts