--- a/hgext3rd/evolve/obshistory.py	Thu Jul 11 15:30:40 2019 -0700
+++ b/hgext3rd/evolve/obshistory.py	Wed Jul 17 11:03:09 2019 -0700
@@ -16,6 +16,7 @@
     patch,
     obsutil,
     node as nodemod,
+    pycompat,
     scmutil,
     util,
 )
@@ -423,15 +424,18 @@
 
 def _debugobshistorygraph(ui, repo, revs, opts):
 
-    displayer = obsmarker_printer(ui, repo.unfiltered(), obspatch=True, diffopts=opts, buffered=True)
+    displayer = obsmarker_printer(ui, repo.unfiltered(), obspatch=True,
+                                  diffopts=pycompat.byteskwargs(opts),
+                                  buffered=True)
     edges = graphmod.asciiedges
-    walker = _obshistorywalker(repo.unfiltered(), revs, opts.get('all', False), opts.get('filternonlocal', False))
+    walker = _obshistorywalker(repo.unfiltered(), revs, opts.get('all', False),
+                               opts.get('filternonlocal', False))
     compat.displaygraph(ui, repo, walker, displayer, edges)
 
 def _debugobshistoryrevs(ui, repo, revs, opts):
     """ Display the obsolescence history for revset
     """
-    fm = ui.formatter('debugobshistory', opts)
+    fm = ui.formatter('debugobshistory', pycompat.byteskwargs(opts))
     precursors = repo.obsstore.predecessors
     successors = repo.obsstore.successors
     nodec = repo.changelog.node