mercurial/scmutil.py

--- a/mercurial/scmutil.py	Sun Jan 14 23:59:17 2018 -0800
+++ b/mercurial/scmutil.py	Sun Jan 14 00:02:40 2018 -0800
@@ -1260,7 +1260,8 @@
                 repo.ui.status(_('obsoleted %i changesets\n')
                                % len(obsoleted))
 
-    if obsolete.isenabled(repo, obsolete.createmarkersopt):
+    if (obsolete.isenabled(repo, obsolete.createmarkersopt) and
+        repo.ui.configbool('experimental', 'evolution.report-instabilities')):
         instabilitytypes = [
             ('orphan', 'orphan'),
             ('phase-divergent', 'phasedivergent'),