--- a/hgext3rd/evolve/obshistory.py	Wed Mar 11 18:09:11 2020 +0700
+++ b/hgext3rd/evolve/obshistory.py	Wed Mar 11 19:05:45 2020 +0700
@@ -438,7 +438,7 @@
     """ Display the obsolescence history for revset
     """
     fm = ui.formatter(b'debugobshistory', pycompat.byteskwargs(opts))
-    precursors = repo.obsstore.predecessors
+    predecessors = repo.obsstore.predecessors
     successors = repo.obsstore.successors
     nodec = repo.changelog.node
     unfi = repo.unfiltered()
@@ -461,8 +461,8 @@
         markerfm.end()
         fm.plain(b'\n')
 
-        precs = precursors.get(ctxnode, ())
-        for p in sorted(precs):
+        preds = predecessors.get(ctxnode, ())
+        for p in sorted(preds):
             # Only show nodes once
             if p[0] not in seen:
                 seen.add(p[0])