--- a/hgext/evolve.py	Thu Jun 18 16:13:15 2015 -0700
+++ b/hgext/evolve.py	Thu Jun 18 16:13:35 2015 -0700
@@ -421,7 +421,8 @@
 
 def _allprecursors(repo, s):  # XXX we need a better naming
     """transitive precursors of a subset"""
-    toproceed = [repo[r].node() for r in s]
+    node = repo.changelog.node
+    toproceed = [node(r) for r in s]
     seen = set()
     allsubjects = repo.obsstore.precursors
     while toproceed: